Lots of questions on pond design.
  • NeliNeli November 2011
    Posts: 1,205
    First of all U made my head buzz. He he he! (i have a toothache since saturday, now the pain has doubled) Too much to digest, and I am not sure I will manage. Going to read it all over again, few times so I get it in small doses some how, maybe I will manage to chew it
    I think we need to do it again in English for dummies... he he he!
    Let me try...
    1. Thanks for the excel doc. I will try to be brave and use it, but U will have to check me up.
    But I find your explanation very comprehensive... so I will try.
    I have some graphs for the different friction coefficients for different fittings, at different pipe diameter. Do U use any of this or not.?
    I see U add all the energy losses to get the total loss....so I need to add to that just the losses due to additional fittings.... U have done most of the job.

    Quote:
    Now this is the elevation head difference between free surface water level in the pond and the free surface water level in the barrel required to overcome all the losses. That is if you free surface water of the pond is higher than the barrel free water surface level by 173.45mm. NO FLOW!!!. It is in equilibrium. At this difference in levels between the two free water surfaces….your return flow (which will be the velocity head) is resisted by the friction forces created in the flow. Thus NO FLOW.

    This I dont get! Did not manage to digest it. This is what I think but then I am sure I am wrong....:or dont understand what U mean...
    Is the head not the difference between the pond level and filter level????? Is it not that when the pond level is higher, the head is higher, and the water has higher potential energy...there for the flow will be higher???? Be patient with me, I have just been learning this things in a panic mode so I dont mess up....
    Do U mean that the pond level has to be higher than 173.45 for flow to occur????
    question: (stupid one) : since my pond level and the filter level will be the same height, the 173cm will be the dynamic (???) head loss that I will get in the filter?

    Quote:
    Side note:
    Your return piping from the barrel to the pond has not captured in the calculation so far as I don’t know how you want to pipe return to pond and its length and how many bends.

    I would use gravity for all returns... Have not calculated yet how many inch pipe to use...so I get a flow velocity through the returns, minimum of 378 cm/s, which corresponds to a
    flow rate of 19 L/s for each TPR, that will also determine the number of TPR I will use too.
    So I will have to see what I can get available from the pump for the TPR minus the skimmer...

    Quote:Therefore to overcome the draw down, you need to have an elevation height of your pond free surface water level higher relative to the free surface water level in the barrel by 175mm + 40mm = 220mm.

    That is not very good news... 22cm draw down????? And that is exactly what I was trying to caution my friend about on the other thread, but I was not taken seriously.....
    Now since I can not afford a draw down of 22cm in my vortex...I will need to find a different solutions.
    So Since some values are constants and some I would not like to change, the only way I see to reduce the draw down is by:
    -reducing the flow through the BD pipes,
    -or connecting 2x4" pipes to each BD (we dont have bigger size pipes here) (again no win with this for I will reduce the self cleaning ability of the pipes.

    Quote:
    When we pump water into the main pond, the water level will rise if the main pond outlet is shut off. However, we have bottom drain to drain water into the 1st chamber. The water will equalize to the same level as the main pond if the 1st chamber is not stuff with material to create flow resistance.

    Now this one has confused me again...how will the water in the first chamber equalize to the level of the pond???? Is there not going to be head loss??? (lower level in the filter)
    22cm in my case???? What am I not digesting here????

    Quote:
    Bernoulli’s principle described that when the velocity of a fluid decreases, the pressure exerted by that fluid increases. In other words, Pressure + (kinetic energy/volume) = constant. By the conservation of energy theory, the total energy line (TEL) is the same at the main pond and the 1st chamber and in fact to all the chambers. This is constant. Any change in the velocity of the water as it flows through the chambers will result in a difference in pressure head to balance the energy level back to the total energy line.

    So in English for dummies (like me) What U are saying that there will be additional friction losses from chamber to chamber, which will result in head being highest in the last chamber???? And it still needs to be calculated..and to be considered..

    quote:
    Assuming the probability of that blockage happening is real. Assuming…Over the years you did not flush your system….. As the waste turned to sludge occupying a proportion of the pipe cross sectional area as it accumulates, the overall cross sectional area of the pipe will get smaller. When the pipe cross sectional area get smaller and smaller, you will find from the continuity equation (Q1=Q2, where Q = Flowrate and Q=VA, where V = velocity and A is the cross sectional area) the velocity will increase to maintain continuity in the flow rate. You will eventually have a cleansing velocity to dislodge the sludge. There is a reason to install a bigger diameter pipe for BD.

    Not in my situation... That will not happen...I will have a skimmer=water fall=overflow.
    so since the cross section A will be reduced, I might get lower/reduced flow rate, since my pond water level will raise and increase the discharge of the skimmer (which can easily compensate 2 BD flow), and I will never know I have a blocked BD since the flow through the skimmer will compensate for the missing flow through the BD...For short: I can block both BD and I will still have the same flow through the filter.

    Quote:
    Now…. your calculation on the flow rate…with a velocity of 0.75m/s to a 4” pipe and assuming no energy losses, it should read 21,1950L/hr not 25,000 L/hr.
    I was doing the calculations in my head and for simplicity multiplied /converted the gallons 1g=5l.
  • NeliNeli November 2011
    Posts: 1,205

    Quote:
    Based on what I read your conceptualized plan, I don’t think your pump capacity will be adequate simply because your head loss in your system piping network will be very BIG. Serious, it will be very BIG.
    Now here I am lost and scared....and more confused:
    The bigger the pump discharge, the bigger my draw down in the filter will be... (is this a correct assumption?)
    Why do U say that? I plan to feed TPR by gravity...,build a higher chamber (than the pond) to create head for the TPR, how high? ( thats where U come in: Heeeeeeeeeeeeeeeeeeeeelp!)
    I will need to calculate how much discharge I will get eventually from the pumps, minus bakki, and see /calculate for how many TPR this flow will be enough for my desired velocity through each TPR.

    Quote:May I know what make you come to the conclusion that you will have very little head loss on the pump side? Your pumps need to take care of many things….for example the suction head, the discharge head and all the frictional losses in the system piping network and all the entrances and exits losses and other minor losses.

    My submersible pumps will pump over a distance of 20-30cm max through a 4" pipe. That is why I said it will have minimal losses. It is not like I will pump through the TPR pipes with the pump.I know I will have to reduce for the head loss due to the height of the chamber where my water will pump too, but it is hard to get less losses than this.

    Quote:
    You should not size your pumps based on the volume of your pond and its filtration components volumes. I noticed many of my friends did it that way and eventually they don’t have the water volume turnover rate as after deducting all the losses and what not….very little remain. Your biggest killer will be your bakki shower. Any you working in a confined space that warrant and justify for the bakki shower to take priority? The science to it is interesting though.

    I agree with U. But there are other things to consider too. Economics! I am trying to see what is the most economical way to turn over the water in the pond without compromising the sweeping capacity of the pond, ease of maintenance and performance of filtration... So I am trying to work in reverse some how. I dont believe that pump power is the main thing affecting the performance of a pond. Pond design, filtration, and piping, type of flows/velocities... plays major role too.

    Quote:
    My view on how a skimmer should be designed depend a lot on how we want to control and direct the surface water flow in relation to the water body circulation. It is part of the surface water management design. For time being….IMHO I think we should concentrate on the water system design 1st and remodel your pond overall system is a better approach to have an optimum design based on the given constraints you are working on.

    I am open to suggestions, and I think U have the capability, brains, intelligence, and knowledge...to be able to do just that (quote:remodel your pond overall system is a better approach to have an optimum design based on the given constraints you are working on.)

    quote:
    Do I get U right? I need a flow of 6000gph in each BD pipe?
    That is right if you want a self cleansing velocity to be attained in the BD. As I said before….it is not practical. By default we FLUSH our system thus we can generate higher velocity to clean the BD.

    This is what I wanted to hear, and was about to suggest on the end... which I am still going to do...I was just giving small hints above when I said that I will need to reduce the flow through the BD's but did not wanted to sound too big headed (which I am) and as if I dont want to listen to some one who knows what he is talking about.
    I believe the biggest challenge is to design a pond that is:
    -economical to construct and maintain
    -not to the detriment / balance of easy maintenance.. health of Koi...
    -.....and so many other things
    It is very easy to blast lots of water in a pond...but the best for me is to find the balance between all factors, without serious compromises.

  • NeliNeli November 2011
    Posts: 1,205
    quote:
    On the 1hr turnover rate, hehehe…..yes, it is mind bogging to me to how that magic figure comes about?

    BTW that is not a magic figure for me...I was even planning on ones every 2 hours, and dont see much wrong with it.

    quote:
    I recall a detention time of around 15mins is a good consideration. May be someone well verse in this area can elaborate further.

    I have those figures somewhere, but need to look for them. It is 02 (after mid night now) But I am enjoying your post so much that I can not stop.

    Quote:
    Reading your depicted pictures, I don’t see you have space constraint. 1st is to throw away the Bakki shower thing. It need a strong pump will a lot of head to pump to the designed height. Do you know the engineering of it to produce a good design of it? It is horrible and an eye sore. It is noisy too. It is like a cooling tower sitting in an open area. It is imposing and IMO it will not blend well into your environment…..but I like the science that goes with it. hehehe….

    I just did a bakki, huge... 3m long...U can not hear it...(I put muffler on top). I am not too sure how well I know the engineering of it....but not too bad..I think I posted here so U can check it up.
    I have a good plan to hide it...
    Now do U remember where I am? AFRICA! = HOT!= cooling tower....no????
    high temperatures= low oxygen saturation level and bakki= oxygenation...
    That is my main consideration.Not talking about nitrate removal which is under debate.. But for the rest as usual U are right.

    Qute and answer:
    1st is with a Reynolds number of approximately 6000……we already into the turbulent flow regime. It is in an unsteady state flow but then in the hydrodynamic analysis…..assume steady state conditions. The formulas used are all empirical in nature to the specific size under experimenting.
    Agreed...but it i a comparison study...
    Do you know what your tank Ct value will be?

    As u know reinolds number affects Ct value (the lower the better), but I would expect values of 0.09-0.1 max for this type of pond flow.
    Remember : The tank resistance coefficient (Ct) has been demonstrated only
    as a useful tool for the evaluation of tank
    configurations in both rectangular tanks with rotating
    cells and in circular tanks. Ct values are very useful for
    adjusting the desired average velocity in the tank.

    Do you know what the fish swim speed he taken into account? He has not thrown a single fish into it and tells us how the shits will obediently swim to the inlet of the BD.

    That is even better since the swiming action of the fish contributes to the movement of the waste towards the BD. Remember it is comparison study, and if U look at his references U will find that there are many other studies done on it on larger deeper pond. I looked at all of them...Did U see the pond for which I gave U a link? The one that is almost the same...

    His experiment tank is relatively swallowed. The fluid dynamic in deep water tank is different from a swallow water tank.

    Agreed. But but but ... he he he! comparison study????

    You will need a lot of energy to drive into a vortex condition. Those baffles plates that you are thinking of introducing IMO will be too challenging to determine a proper size and the fluid mechanic to it is not so simple as you think it will be.
    The principle is think of the baffle is not too hard, as long as it is in the correct place. There is a diagram there how to construct it. If U look at the link of the pond for Kent... he has something looking like a baffler in the pond...not mentioned as one though.
    In my case a baffle will help me hide my piping...
    Look at his reference links. There are many similar studies done, and I suspect Kent is influenced by it too.
    Google this. If I remember well this a study done on larger deeper pond: Burrows and Chenoweth, 1970; Tvinnereim, 1988;
    Timmons and Youngs, 1991).
    Quote:
    What we want is a laminar flow….in a laminar flow the motion of particles of fluid is very orderly with all particles moving in straight lines parallel to the pipe wall or the direction of flow.

    Steady flow means that the discharge is constant with time. Uniform flow means that the slope of the water surface and cross-sectional flow area are also constant in the length of the flow. We want this type flow not the turbulent type.

    I agree with this 1000%.... that is where I want to find a solution for in order to get best value for money.... And I know where U are going with that... and I like the direction U are taking...
    I like also the way U are thinking...U let me drawn in my own s....t just to come and fish me out, and show me the right way.... he he he!
    It is 03 here now. Time to dudu. I am not going to post my conclusions, for I fear I will spoil your fun and mine too. But I dont like great minds, I LOVE them.
    And I enjoyed each word u posted, and learned a lot.
    THANKS! I got my new camera today from Hong Kong....and it came with a hat...So now I will take a nice hat (addidas) off to U.
    Dont think I am too argumentative....It is asking, not arguing...

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  • NeliNeli November 2011
    Posts: 1,205
    There I go again, Brother Harry! I have just seen that I have one more page to enjoy...starting with No7.
    Well!!!??? it happens... I will not sleep tonight...in the name of a good cause, I can not leave it for tomorrow. It is too good , to leave for tomorrow..

    quote:
    When I comment on your pond layout…The architecture context of your arrangement is rigid and too formal. It is like fish farming arrangement where they regime it that way. The spatial relationship of your pond with respect to the planting does not correlate. It does not draw visual interest and I don’t think it will blend in well with your given environment. With the bakki tower boldly on one half of the overall pond….it is not balance.

    The pond is in a totally empty plot...For me making it beautiful is the easiest part of the pond construction.... the hardest is making it efficient. I just made(last year) a beautiful pond (IMHO) that is totally inefficient.This one is for my babies: what is best for them!
    The Koi part is larger than the water garden. There will be a wall infront of the bakki, and the filtration part with bakki will be in the end of the old plot.
    To be honest I left the beauty part last, in order to design it around the filtration, and as I said (not boasting) the beauty part will be the easiest for me. (or I hope so)
    But I am open to suggestions, since I believe 2 heads are better than one...
    This is my current pond:
    image
    Maybe if U see it U will know why I want a formal pond now.
    This are some ideas I like:

    image

    This is some thing I toyed with but not sure...
    image
    But this is the kent W pond I was talking about.
    image
  • NeliNeli November 2011
    Posts: 1,205
    Continued:
    Quote:
    Try to imagine converting this pond with the foreground a koi pond with an infinity outfall via a weir discharging into a long gutter or a collection system way and a lower pond in the distant harmonizing with all the planting that you wish to incorporate.

    I dont understand this....

    You can even have both sides to be guttered as part of the water return flowing back into your koi pond with specific points of discharge to promote some drama in your pond. Some water planting can in here too. Timber deck part of the pond with a sitting area and walkway to be nearer to your kois and plants and for maintenance of the pond in the middle.
    What is guttered? I dont know this word.
    I plan to have a infinity water fall in the middle of the wall but in some unusual design...not horizontal... but I am leaving that for last, since priority No1 is efficiency. Ones I have done that I will move to the beauty part...

    Design for a “plug flow” in your pond. If only I have the space that you have, I would have designed it so.

    What is plug flow?

    I will throw away the bakki shower thing but if you like it so much….perhaps you can create a waterfall structure to shield it.
    Yes! That is goooood!

    Quote:
    On the energy losses, go and download your prefer pump performance chart. You will see on the Y axis it represent head and the horizontal axis the flow or discharge. Estimate the total length of all your piping works and for each bend or elbow you add 25D(where D is the diameter of the pipe) to the calculated straight run of your piping and for any T-tee you used, you add 60D to be the piping length again. For the ball valve and gate valve use full bore type. …so no need to allow for energy losses. Use the Hazen Williams formula to determine the head loss. Lastly add the pump suction head and the bakki shower height as head into it. Check and see how big the head loss is.
    OK this good... very good... what units will I get for example: 25D= 25* 110= 2750 mm?
    Pump suction head (submersible pump) = level in last filter calculated (????) after head loss (or estimated) - level of chamber feeding by gravity the returns *-1..Is that correct?

    Quote:
    I don’t think you need to use vortex. Go and read a bit on sedimentation tank design or a primary sedimentation clarifier. They are not out dated. You can incorporate this type of sediments treatment into part of your pond…..as you are planning to subdivide it. Can you show me what Izeki looks like?

    I like that too... very much... Does it not need to be very large, and does it not need to much water for flushing??? I dont know... Just imagining. But it will be much easier for me to construct than a vortex. Need to research it... Did not think of it... U have a point here.
    Will do that tomorrow, and report back.
    TPR is tangential pond return. ( at an angle)
    What is lapping?
    And what is this:
    The “plug flow “system is a much better choice. It can be easily design, controlled and managed.
    I dont know "plug flow"???? Maybe we know it by different names?
    Remember : i can not buy any related Koi products here.
    This is izeki:
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  • NeliNeli November 2011
    Posts: 1,205
    This is my settlement chamber (or at list that is what I call it) Water from the bottom goes inside, through pipes on the bottom with holes on them... but it keeps my bottom clean. I built my pond with no BD... new nothing, had no internet, and no one to ask.. Can U see how clean it is? My pond is the same... Most of it done DIY, my own inventions..... due to desperation.
    image
    Post edited by Neli at 2011-11-08 05:52:08 pm
  • harryyewharryyew November 2011
    Posts: 393
    Good day to you Neli

    Lol…You will manage for sure.

    Quote:
    ……. I will try to be brave and use it, but U will have to check me up.
    I have some graphs for the different friction coefficients for different fittings, at different pipe diameter. Do U use any of this or not.? I see U add all the energy losses to get the total loss....so I need to add to that just the losses due to additional fittings.... U have done most of the job.

    Ok. Will check for you. Are you referring to the Moody chart? No need to use that. For your system piping delivery network, you use Hazen William Formula is good enough. It is simple to use. You need to obtain the friction factor values of C. If you are using PVC, then C value =150. Yes, determine the balance energy losses in your piping delivery network and fittings.

    Quote:
    This I dont get! Did not manage to digest it. This is what I think but then I am sure I am wrong....:or dont understand what U mean...
    Is the head not the difference between the pond level and filter level????? Is it not that when the pond level is higher, the head is higher, and the water has higher potential energy...there for the flow will be higher???? Be patient with me, I have just been learning this things in a panic mode so I dont mess up....
    Do U mean that the pond level has to be higher than 173.45 for flow to occur????
    question: (stupid one) : since my pond level and the filter level will be the same height, the 173cm will be the dynamic (???) head loss that I will get in the filter?

    Sorry for the confusion. I can see how my explanation is confusing. Let me try to put forward this explanation for your understanding.

    Yes, the head is the difference between the pond level and the filter level. Yes, when the pond level is higher, the head is higher, and the water has higher potential energy…. therefore the flow will be higher. This static head of 173mm is actually the pressure head required to overcome all the energy losses at the suction end of the pump.

    Yes, since your pond level and the filter level will be the same height, the 173mm will be the dynamic head loss that you will get in the filter if you do not have any further pressure head to drive the body of water to higher elevation in the filter. You have graduated. Hehehe….

    Bernoulli’s equation states that at any point in an open channel or piping works with open ended condition of a flowing fluid the following relationship holds.

    P + mgh + ½ mv2 = constant

    P is the pressure, h is the height, v is the velocity, and m is the density at any point in the flow.

    Now if the elevation of the water is to remains constant and let say the there is a slight different in elevation of the pond and the barrel small enough not to change the gravitation potential energy of the water much, you just ignore it and you have this equation to look at.

    P + ½ mv2 = constant
    If I divide the above equation by mg (m=density, g =gravitation acceleration) throughout the above equation, I get

    P/mg + v2/2g = constant.

    Now this p/mg is the head measured from the free surface water to the point of each of the rim of the inlet and outlet.
    Now….let us have a datum level reference from a level below the BD inlet level to the rim of BD inlet level as “z”

    We then have Harry’s equation = z + P/mg + v2/2g = constant. Hehehe…. See attachment

    image
  • harryyewharryyew November 2011
    Posts: 393
    Quote:
    I would use gravity for all returns... Have not calculated yet how many inch pipe to use...so I get a flow velocity through the returns, minimum of 378 cm/s, which corresponds to a flow rate of 19 L/s for each TPR, that will also determine the number of TPR I will use too. So I will have to see what I can get available from the pump for the TPR minus the skimmer...

    If you are using gravity for all returns…. Then use Manning’s formula to calculate your average velocity. The roughness coefficient takes 0.009.

    Note: Are you refereeing to 378 cm/s (i.e. 3.78m/s) or it should read 378mm/s(i.e. 0.378m/s). If you are actually planning for 387cm/s then scouring will occur, if 378mm/s then no self cleansing of the piping works. Using at least 0.8m/s.

    Quote:
    That is not very good news... 22cm draw down????? And that is exactly what I was trying to caution my friend about on the other thread, but I was not taken seriously.....
    Now since I can not afford a draw down of 22cm in my vortex...I will need to find a different solutions.
    So Since some values are constants and some I would not like to change, the only way I see to reduce the draw down is by:
    -reducing the flow through the BD pipes,
    -or connecting 2x4" pipes to each BD (we dont have bigger size pipes here) (again no win with this for I will reduce the self cleaning ability of the pipes.

    May be he has sufficient big pumps to overcome the losses. Not efficient though.
    You can lower the vertical up-stand pipe by the calculated amount. Hehehe….

    When I read your replies and notice you are think of the hydraulic in term of energy conservation law…..you are on the right path. Energy equation always holds truw, provided proper allowance is made for energy losses.

    Quote:
    Now this one has confused me again...how will the water in the first chamber equalize to the level of the pond???? Is there not going to be head loss??? (lower level in the filter)
    22cm in my case???? What am I not digesting here????

    When there is no energy loss…..everything will be equal. Look at Bernoulli’s equation or alternatively you can refer to Harry’s formula and the diagram. All Potential energy is transferred to Kinetic Energy and then back to Potential Energy!!! Got it?

    Quote:
    So in English for dummies (like me) What U are saying that there will be additional friction losses from chamber to chamber, which will result in head being highest in the last chamber???? And it still needs to be calculated..and to be considered..

    Yes….Your have obtained your Master degree!!! Congratulation.
    This part of the engineering is more towards hydrology. Here you don’t use Hazen-Williams formula ok. Use Manning’s formula to get the velocity and then use Harry’s formula to determine the respective drawdown. Continuity equation Q=VA still holds.

    Quote:
    Not in my situation... That will not happen...I will have a skimmer=water fall=overflow.
    so since the cross section A will be reduced, I might get lower/reduced flow rate, since my pond water level will raise and increase the discharge of the skimmer (which can easily compensate 2 BD flow), and I will never know I have a blocked BD since the flow through the skimmer will compensate for the missing flow through the BD...For short: I can block both BD and I will still have the same flow through the filter.

    Not exactly…unless you have a dedicated pumping rate that is near to the main pond pumping rate. When the pipe overall internal diameter get smaller the velocity will increase to maintain continuity flow. The equation of continuity is the law of conservation of mass in fluid dynamics…..Q1=Q2 or velocity(1)*Area(1)=velocity(2)*Area2. Now this is true if it is a laminar flow and the fluid is incompressible.

    I will discuss on the skimmer thing when the opportunity arises. For time being consider it as a bonus to your system. It is not as simple as placing a box and have a pump and pump it to the water fall. The rate of your pumping, the placement of your air supply will influence the effectiveness of the skimmer performance. Coastal engineering design will come into play. Waves equation……Hehehe……

    Quote:
    Why do U say that? I plan to feed TPR by gravity...,build a higher chamber (than the pond) to create head for the TPR, how high? ( thats where U come in: Heeeeeeeeeeeeeeeeeeeeelp!)
    I will need to calculate how much discharge I will get eventually from the pumps, minus bakki, and see /calculate for how many TPR this flow will be enough for my desired velocity through each TPR.

    Hahaha…..before I can come in…you are creating so many energy losses that there is very little remain for you and me to use. hehehe
    There will be losses again (frictional is the main one) when you discharge via TPR or any piping return to the pump. This time it is pure gravity flow there is no back pressure to keep a positive head to push forward. Whereas in a pump you can have that. The water level in the temporary holding tank will fluctuate as it drains, you will also experience fluctuating velocity. The higher you go….the more pumping head is required. When the pumping head increases, you will have lower flow. Can you see how inefficient the use of energy we have drained the energy away as we transport the water from one location to another.
    Please download a pump performance chart and have a look at it. You will then understand what I am trying to tell you…..What brands of pump are available there?

    Quote:
    My submersible pumps will pump over a distance of 20-30cm max through a 4" pipe. That is why I said it will have minimal losses. It is not like I will pump through the TPR pipes with the pump.I know I will have to reduce for the head loss due to the height of the chamber where my water will pump too, but it is hard to get less losses than this.

    How are you going to get water up high to the bakki shower and the waterfall and a holding tank with return via TPR right? Do you use the same pump or another dedicated pump? Think of the elevation head loss you need to overcome.

    Quote:
    I agree with U. But there are other things to consider too. Economics! I am trying to see what is the most economical way to turn over the water in the pond without compromising the sweeping capacity of the pond, ease of maintenance and performance of filtration... So I am trying to work in reverse some how. I dont believe that pump power is the main thing affecting the performance of a pond. Pond design, filtration, and piping, type of flows/velocities... plays major role too.

    The traditional way is the most economical design.
    Let assume you get everything rights except the pumps and the strategic number you should have including its placement……the pumps is the HEART of the system. If the heart cannot pump proper and affect your system wide networks of functionality. Your pond is myocardial infarction already. Then “THE END”….finish story, sunset and actors and actresses all bye bye already.
  • harryyewharryyew November 2011
    Posts: 393
    Quote:
    I believe the biggest challenge is to design a pond that is:
    -economical to construct and maintain
    -not to the detriment / balance of easy maintenance.. health of Koi...
    -.....and so many other things
    It is very easy to blast lots of water in a pond...but the best for me is to find the balance between all factors, without serious compromises.
    Agreed. A solution must be close to optimum to start with, as retrospective fixes are never wholly satisfactory.

    Quote:
    BTW that is not a magic figure for me...I was even planning on ones every 2 hours, and dont see much wrong with it.

    Your rationale on this.

    May I know what is your estimated detention time you have calculated for your pond?

    Quote:
    I just did a bakki, huge... 3m long...U can not hear it...(I put muffler on top). I am not too sure how well I know the engineering of it....but not too bad..I think I posted here so U can check it up.
    I have a good plan to hide it...
    Now do U remember where I am? AFRICA! = HOT!= cooling tower....no????
    high temperatures= low oxygen saturation level and bakki= oxygenation...
    That is my main consideration.Not talking about nitrate removal which is under debate.. But for the rest as usual U are right.

    Please show me some pictures of it.

    Ok. Now I know. Hehehe….May I know which part of Arifca.
    How hot is there and what is the usual humidity you are having there. Do you know the wet-buld temperature there. If it is humid there, do you experience a feeling of cooling effect when wind glow over your skin? What is the water temperature there in the open.
    OK we are now going into the thermodynamic.
    I am very sure the bakki tower or the shower as a cooling tower will not work. In fact I think it will work against your assumption.

    Quote:
    Agreed...but it is a comparison study...

    Hmm….to me the comparison is not representative at all. The model simulation again cannot be exploded to represent the actual behaviour of a fish pond. If he has used the fish waste and show us how the wastes are directed to the centre and the rate of it, I would have given further consideration.

    If all this circular rotating raceway is so good for a rectangular, I would expect the farming industry across the world implementing it. I did not read the author’s links to other people work but from his report I read he is quoting everybody all over the report. To me this is an indication of his experiment is not conclusive and definite as to what he want to proof. He needs to rely on others people report to substantiate and justify his recorded observations.

    Quote:
    Did U see the pond for which I gave U a link? The one that is almost the same...

    I have read all that you have provided a link but I might have missed. Can you please provide me to the specific link you are referring? Would like to read.

    Quote:
    Dont think I am too argumentative....It is asking, not arguing...

    No…not at all. Nice hat.
    Your current pond pic…..I must said….Not bad photography skills and your landscaping is nice. How deep is this pond? May I know what are the things you find this pond inefficient?
    Is the river marking on the pic is where you will provide a river to your proposed new pond?

    Quote:
    I dont understand this....
    Can you take a few pictures of the empty plot of land where your new pond will be. Please indicate where is north in the picture.
    I just finish drafting 3 affidavits in replies to the defendants.
    When this is free off the way, I will try to draft something for your further consideration.

    Quote:
    I plan to have a infinity water fall in the middle of the wall but in some unusual design...not horizontal... but I am leaving that for last, since priority No1 is efficiency. Ones I have done that I will move to the beauty part...

    Ok, but remember as a rule of thumb, a good sheet waterfall you need around 100 to 150GPH per inch of the waterfall. Hmm…I will wait to see the non horizontal arrangement. I am interested to learn this.

    Quote:
    What is plug flow?
    Plug flow is a simple model of the velocity profile of a fluid flowing in a pipe where the velocity of the fluid is assumed to be constant across any cross section of the pipe perpendicular to the axis of the pipe. You can design your pond to have this type of flow.

    Quote:
    OK this good... very good... what units will I get for example: 25D= 25* 110= 2750 mm?
    Pump suction head (submersible pump) = level in last filter calculated (????) after head loss (or estimated) - level of chamber feeding by gravity the returns *-1..Is that correct?

    Yes. 25d-25*110mm=2750mm
    Suction head and discharge head = Total static head. Since the submersible pump is immersed in the chamber. Your static head is = Discharge head – suction head. Suction head is measured from the free water surface level in the pump chamber to its suction inlet. Discharge head = the vertical height from the pump inlet to where you are discharging it out.
  • harryyewharryyew November 2011
    Posts: 393
    Quote:
    What is lapping?
    Where the reinforcement bar over lapped each other. Concrete cannot take tension…so we introduce reinforcement bars to address the tensile stress. The minimum lap is to ensure the bonding stress between the reinforcement bar and the concrete surface can be developed accordingly.

    Quote:
    The “plug flow “system is a much better choice. It can be easily design, controlled and managed.
    I dont know "plug flow"???? Maybe we know it by different names?
    Remember : i can not buy any related Koi products here.

    Now…. I name it plug flow….when it is implemented (of course after we can proof it will work and again we can do a small tank for comparison before full scale implementation. It will thereafter name as “Neli flow”. It like the flow in an open channel but the streamline flow-lines are evenly distributed across the cross sectional of the flow. We go into hydrology to design this. No need special koi products.

    Thanks for showing me the izeki. Will have to examine it in closer detail.

    Cheers
  • ashfaqashfaq November 2011
    Posts: 791
    Neli, trust me, its lots of lots of Questions :-D
    Thanks,
    Ashfaq from India-Chennai
  • NeliNeli November 2011
    Posts: 1,205
    Ashfaq, U know how I messed up the first time... Dont want a repeat... Better measure twice and cut ones. 8-> (fubar) (sweat) :/
  • harryyewharryyew November 2011
    Posts: 393
    Ashfaq….

    before she questions this time….I take the opportunity to answer first…..after all we are in the KoiAnswers forum. lol

    Neli


    I notice that you have not actually gone into the details as to how you will eventually achieve good water quality. IMHO this needs to be prioritized over other matters before going into the hydraulic.

    You will eventually operating an open aquatic system. It can be a circular mixed raceway, stream-flow or plug flow. I like the approach consideration to have an appropriate design that meets the needs of your pond and as a good pond-keeper that don’t need those high tech wonder products that requires having a crew of people for maintenance.

    I find from the many discussions here and elsewhere, many pond-keepers have actually become a permanent enslaved filter keeper….hehehe….

    When you put forward your proposal for comments, I was telling myself…..this is the type of pond system I would love to have ….simply because it address the 2 basic types of ponds in one goes…..namely garden pond and fish displayed pond. The introduction of an appropriate size of this water garden pond into the overall pond mimics nature in many ways. To me…. I don’t have that large piece of land…. else I would have designed and built my pond very similar to what you have put up for discussions.

    If we examine and ponder what is a pond life….My view is that it is the plants and not the FISH. The fishes are just inhabitants.

    To me there is no such thing as a perfect or ideal pond that can be used universally across the continents and the many constraints we have in the pursuit to achieve an appropriate designed pond. Many of us are actually building a fish display pond. No plant to very little are incorporated. I believe this come about because not many people has been given an informed choice and those that love fishes don’t like planting or rather have little knowledge on plants and flowers.

    The heart of the system has been discussed and I think you need to identify your prefer life support system…….i.e. Filtration system. Can you provide me a link to Eric (raceway filter)?

    With your wide readings and the experiences gained from your previous pond design, I don’t see you have meticulously checked like you did for the fluid hydraulic so that you can minimize your risk exposure of not achieving your primary objective.

    There are so many solids to take care whether it is introduced externally or internally into the pond. I know….I know….many pond-keepers will say…..all this rubbish have to go…..hehehe…we all want crystal clear water with good water quality parameter to go with it. To achieve crystal clear water is easy. Good water quality part is difficult. Take my newly constructed pond as an example. I have super crystal clear water….but after all the testing….my alkalinity reading is not within range. Hehehe…

    In your chosen system (i.e. fish display pond + water garden) they will works on a very different set of ecological rules. A fish display pond equates to be like an indoor aquarium in reality. They are generally overstocked…..naturally their line of thinking will be to remove all the shits (ammonia concentration, low DO, disease & etc) ASAP and become priority NO 1. For those more serious pond-keepers they will want super clear view and I see so many inventions have been tried on to achieve this goal.

    On the other extreme of a garden pond….the solids (big or small) are integral part of the ecology system. Decaying materials are allowed to float and eventually sink to the bottom of the pond. The water column is usually tinted greenish cast and turbid. Well this is not dirty but represent the pond is alive, hahaha…..it is filled with bacterial and planktonic activities. Other wildlife…will also take up residence in this type of pond.

    Today, commercial mechanical filtrations are aplenty to choose from. IMHO, I would bravely conclude many of these filtrations work for rather a short time and not suitable in the long term…low maintenance operation outdoors consideration.

    When you have done some research on sedimentation tanking system or clarifier….you will find they address solids removal by 3 basic methods. They are as follows:

    1) manually removing it
    2) coarse screening it
    3) allowing settling

    The 1st method requires no mathematical calculation as merely physical removal and common sense is required. The 2nd method can be experimented by trial and error or alternatively there is a mathematical calculation to estimate its appropriateness.

    Side note:
    I notice many pond-keepers have become obsessed with the notion of screening to the point where they start introducing super fine screens…..and naturally become enslave on a daily maintenance routine. Hehehe… OK. As long as they enjoy it…there is nothing to complain.

    Now the 3rd method is the most challenging task for many fish display pond to achieve its goal. They do not have the space and the volume that you have. As you see…we are actually introducing a recirculation system….many pond-keepers do not know how to take advantage of Mother Nature. Many just leave it to their contractor or pond builder.

    In a laminar flow, you will find solids denser than water leave suspension and drift to the side and bottom of the pond. The forces of gravity and friction cause this to happen. Your system can allow for an “In-pond settling” and it is very effective. You can actually plant dense rows of emergent plants near water inlet and outlet…which can be viewed as a vegetative screen. This vegetative screen reduces turbulence, enhance settling fine particles. As long as you provide basic aeration to the settle materials….it should not have deleterious effects.

    Now…”In-pond settling” in a fish display pond is not effective simply because this pond is always turbid as there is continuous level of fish activity that never allow settling to occur and worst…the appropriate flow rate was not allowed for or should I say….designed for.

    OK. Ok…I know, I know…by now many have more questions than you….hehehe…for example…..what is the appropriate size to have then for a given pond volume. The rule of thumbs is that to have around 15min water moving through the settling basin and this is estimated for a recirculation rate of at least once every 2 hours. Thus the size of this settling basin should be 1/8 of the total pond volume.

    Ok. There will be some hardcore pond-keepers here which will want to have an example. Say, your pond volume is 48m3, then your settling basin volume should be 1/8*48= 6m3.

    Reaching this point….some may have by now confused…as they want to know what happen if the turnover rate is 1 hour. The answer to that is the volume should be 12m3. Gosh!!! That is as big as my main pond. Yes, that is for a 48m3 pond with a 1hr recirculation rate.

    Effectiveness of a settling basin can be improved by introducing incline baffler plates, incline tube settlers and the least efficient brushes. This basically will remove solid and to a large extent finer suspended solid by promoting fine particles to collide with each other to form a bigger lump ….thus settling by its own weight.

    The challenging part will be removing the super fine suspended solid and currently, I believe the sand filtering method is the most practical and economical to have in the system. Many have reported the sand filtering will get blockage over times. I believe this is because in a gravity feed system, it is quite difficult to allow for a minimum of 1 bar (equal 10m of head) of water pressure for back washing. Therefore…deciding the numbers and size of the pump is very important.

    In your overall system….you will have the width and length to allow better settling design…. You can have this basin such that the side where the water enters, incorporate a baffle (if your flow is not laminar) to produces laminar flow and have the floor slopes upwards toward the end where the water exits. Install a purge valve at the deep end for flushing of accumulated material. You can refer to my 1st thread, page 6, where I have shown how I did the estimation.

    May I ask….are you riding on the fact that plants take up ammonia as their primary food source?

    You need to watch out on the rate of vegetative filtration together with nitrifying bacteria in the pond. Plants (depending on the amount you introduce) can take up all the available ammonia especially if your fish stock is low. Ultimately…. you may need to fertilize your pond. Hehehe….


    Cheers
  • NeliNeli November 2011
    Posts: 1,205
    Hi Harry,
    If U just new how eagerly I wait for your posts. I was sick yesterday... Think I have malaria plus toothache. Could not go near the computer...terrible headache...
    I think Your info is so educational to many people...or at list I am glad I am learning so many things that I find important.
    Back to answering U:


    Quote:
    If you are using PVC, then C value =150. Yes, determine the balance energy losses in your piping delivery network and fittings.

    That is the one I was using....140 if I am not mistaken is for steel pipes.

    Quote:
    You have graduated. Hehehe….

    I am a proud student ! He he he!
    Quote:
    Bernoulli’s equation states that at any point in an open channel or piping works with open ended condition of a flowing fluid the following relationship holds.

    P + mgh + ½ mv2 = constant

    P is the pressure, h is the height, v is the velocity, and m is the density at any point in the flow.

    Now if the elevation of the water is to remains constant and let say the there is a slight different in elevation of the pond and the barrel small enough not to change the gravitation potential energy of the water much, you just ignore it and you have this equation to look at.

    P + ½ mv2 = constant
    If I divide the above equation by mg (m=density, g =gravitation acceleration) throughout the above equation, I get

    P/mg + v2/2g = constant.

    Now this p/mg is the head measured from the free surface water to the point of each of the rim of the inlet and outlet.
    Now….let us have a datum level reference from a level below the BD inlet level to the rim of BD inlet level as “z”

    We then have Harry’s equation = z + P/mg + v2/2g = constant. Hehehe…. See attachment

    Now now now???? Tell me if I am "concludaring" correctly:
    Z1=Z2 P1/mg=P2/mg (we ignore head difference)
    Then I will have: (Z=25cm) 25cm + 170cm+2540(2)/2*9.81m/s2=??????
    (at Q=3000gph, V=77f/s=2540cm/s)
    I dont know the name of that coefficient... and I am sure U dont want me to calculate it but to note that it is a constant and make conclusions:
    Change the depth of the pond, and your velocity 2 will reduce by 2g times your depth difference...????? in order to have it constant.
    I just want U to see the links in 3 folders in my favorites that I have been battling with.
    image
    image
    image
    And please post for me pictures of your new pond with diagrams...I am so eager to see it...
    It must be "state of the art" he he he!
    Post edited by Neli at 2011-11-10 03:15:32 am
  • NeliNeli November 2011
    Posts: 1,205
    Quote:
    I would use gravity for all returns... Have not calculated yet how many inch pipe to use...so I get a flow velocity through the returns, minimum of 378 cm/s, which corresponds to a flow rate of 19 L/s for each TPR, that will also determine the number of TPR I will use too. So I will have to see what I can get available from the pump for the TPR minus the skimmer...

    If you are using gravity for all returns…. Then use Manning’s formula to calculate your average velocity. The roughness coefficient takes 0.009.

    Note: Are you refereeing to 378 cm/s (i.e. 3.78m/s) or it should read 378mm/s(i.e. 0.378m/s). If you are actually planning for 387cm/s then scouring will occur, if 378mm/s then no self cleansing of the piping works. Using at least 0.8m/s.

    I am referring to 378 cm/s,velocity discharge needed from a TPR to rotate the water in a cell,3x4m, in order for the dirt on the flow to be swept efficiently towards the BD .

    Here U go:
    Control of velocities
    By calculating a Ct value for the tank, it is easy to
    obtain the desired average velocities by adjusting the
    injected water flow rate (Q) and the water inlet velocity
    (V2). From Eq. (5) we can write:
    V1 ={(2Q(V2 - V1)/ACt}* 1/2
    (dont know how to write the formulas with the key board and english problem (1/2 is like squared))
    When the value of V2 is much greater than that of V1,
    this can be approximated as:
    V1 ={2QV2/ ACt 1=2}*1/2(squared) Eq. (8)

    Q can be related to V2 if the total area of inlet openings
    (A0) are known:
    Q = V2A0
    Eq. (8) can be re-written as follows:
    V1 =(2A0/ACt)*1/2 . V2
    (10)
    This shows that for a specific tank, a specific discharge
    device and a specific water depth, average water velocities
    will be roughly proportional to water inlet velocities.
    As an example, let us consider a tank 16 m long,
    3 m wide and 1 m deep, with four rotating cells (area:
    4 m 3 m) and a discharge jet orifice with a diameter
    of 40 mm. If the required Ct were 0.08, the water
    discharge velocity needed to obtain an average velocity
    42 J. Oca, I. Masalo´ / Aquacultural Engineering 36 (2007) 36–44
    Table 2
    Resistance coefficient (Ct) obtained for each tank configuration
    L/W Ct
    No
    baffles
    One side
    baffles
    Two side
    baffles
    Rectangular tank 0.95 0.14 0.09 0.08
    1.43 0.13 0.09 0.09
    1.91 0.18 0.17 –
    Circular tank – 0.08 – –

    Look at the different Ct values for a round tank and square tunk.... they are all the same, but I dont inow how to post the table. Let me try with a snip:
    already.
    image

    of 15 cm/s would be 378 cm/s, which corresponds to a
    flow rate of 19 L/s and 1.43 water exchanges per hour.
    Relatively high, easily regulated average velocities
    with low energy consumption are usually obtained only
    with circular tanks. The tank configurations analyzed
    here would provide similar advantages in a rectangular
    tank.
    The water velocity must be high enough to make the
    tank self-cleaning, but not greater than the desired fish
    swimming speed. The velocities required for selfcleaning
    have been estimated by various authors
    (Burrows and Chenoweth, 1970; Tvinnereim, 1988;
    Timmons and Youngs, 1991). The recommended
    velocities vary greatly according to faeces characteristics
    (Brinker et al., 2005) and range between 4 and
    30 cm/s. These studies only considered the effect of
    water flow in the tank, disregarding the possible effect
    of turbulence generated by the fish, although this has
    been analyzed by other researchers (Burley and Klapsis,
    1985, 1988; Watten et al., 2000; Rasmussen et al.,
    2005).

    Post edited by Neli at 2011-11-10 03:57:41 am
  • NeliNeli November 2011
    Posts: 1,205
    Hi Harry I have just seen your post. Be carefull your posts will bring more questions from me, and I can be like AK47 and have no shame but ask when I dont get something... He he he!
    I was working on the last part of your post but will ignore it and answer this one...first.
    But let me tell U I like the observations U made....except...that ....u will see just now:
    First note that my first research was on: what shape and flow within pond needs the most economical pump input for the debris on the floor to be swept?
    And trust me I did lots of research on it. Look at the Ct values in the table I gave U.
    For a stream flow design they become much higher, which makes a stream flow pond to need 30-35% more pump input....
    And a lots of research and calculations are done on the matter... and U have to trust me on this one...for a given pump power and volume of pod, the most effective is circular, then square, then a pond with L?W ratio of less than 1.5, and last is raceway or stream flow pond... with highest input energy needed to keep the floor clean....
    Now I am going to answer your new post and then the old one:
  • NeliNeli November 2011
    Posts: 1,205
    Very good observations...

    Quote and answer all in one:

    I notice that you have not actually gone into the details as to how you will eventually achieve good water quality. IMHO this needs to be prioritized over other matters before going into the hydraulic.
    A
    For me good water quality goes hand in hand with effective and timely removal of solids from the pond and that is No1 consideration...due to many factors... deterioration of waste that results in rapid growth of unwanted bacteria...
    second is efficient filtration that will remove all forms of N.
    third is energy efficiency
    4 beauty
    5 and last ease of maintenance ( I have 5 gardeners)
    So every one has to have his own priorities....but some a common to all...
    Q
    You will eventually operating an open aquatic system. It can be a circular mixed raceway, stream-flow or plug flow. I like the approach consideration to have an appropriate design that meets the needs of your pond and as a good pond-keeper that don’t need those high tech wonder products that requires having a crew of people for maintenance.
    A
    Agreed 100%
    Q
    I find from the many discussions here and elsewhere, many pond-keepers have actually become a permanent enslaved filter keeper….hehehe….
    A
    I have put one guy in charge of the pond full time... he he he! (I am a knotty girl)
    Q
    When you put forward your proposal for comments, I was telling myself…..this is the type of pond system I would love to have ….simply because it address the 2 basic types of ponds in one goes…..namely garden pond and fish displayed pond. The introduction of an appropriate size of this water garden pond into the overall pond mimics nature in many ways. To me…. I don’t have that large piece of land…. else I would have designed and built my pond very similar to what you have put up for discussions.

    If we examine and ponder what is a pond life….My view is that it is the plants and not the FISH. The fishes are just inhabitants.
    A
    Pond life is nature in harmony...hard to imitate.. in a recirculating system...
    Q
    To me there is no such thing as a perfect or ideal pond that can be used universally across the continents and the many constraints we have in the pursuit to achieve an appropriate designed pond. Many of us are actually building a fish display pond. No plant to very little are incorporated. I believe this come about because not many people has been given an informed choice and those that love fishes don’t like planting or rather have little knowledge on plants and flowers.
    A
    There are lots of misconceptions regarding plants...Plants = waste products if not properly maintained..
    Plants= sediment trappers.......if not all sediments utilised
    Plants=Hydrogen sulphate production =poison to fish
    Plants = anaerobic conditions=anaerobic bacteria.... harmful to fish.
    Now if U manage to overcome the above negatives... then:
    Plants = beauty
    Plants = nitrate removal
    Plants = oxygenation...
    Q
    The heart of the system has been discussed and I think you need to identify your prefer life support system…….i.e. Filtration system. Can you provide me a link to Eric (raceway filter)?
    Now I am going to give U several links to eric: bad and good.
    A
    U must remember that Peter Waddington is a fantastic Koi keeper...good sales man....is in it for money.....and is not liked much due to the fact that he does not mince his words... (banned from koibito, koiphen and....other forums...)
    http://www.koiphen.com/forums/showthread.php?114750-Eric-filter......is-it-really-progress...
    http://www.ericpondfilters.com/waddy%e2%80%99s-blog/
    http://www.themtherekoyas.com/viewtopic.php?f=5&t=1489
    http://www.koi-bito.com/forum/main-forum/11048-peter-waddingtons-eric-endless-river-concrete-3.html
    I read a lot but dont post much....exception here....
    Q
    With your wide readings and the experiences gained from your previous pond design, I don’t see you have meticulously checked like you did for the fluid hydraulic so that you can minimize your risk exposure of not achieving your primary objective.
    A
    Here I have to tell U some thing U dont know...about my plans....Last...
    Q
    There are so many solids to take care whether it is introduced externally or internally into the pond. I know….I know….many pond-keepers will say…..all this rubbish have to go…..hehehe…we all want crystal clear water with good water quality parameter to go with it. To achieve crystal clear water is easy. Good water quality part is difficult. Take my newly constructed pond as an example. I have super crystal clear water….but after all the testing….my alkalinity reading is not within range. Hehehe…

    A
    I have my pond PH at 9+ for the past 1 year... My source water has very high PH...I have no problems due to that....maybe in the long run????? but I would like U to check your KH to buffer your pond...U need high KH in order to avoid PH crush... and high KH help with high PH. I would not advise u to artificially regulate your PH. It is not easy...and U will never stop...
    Is it because of the concrete in the new pond or source water???? There are solutions for that...Let me know. (I think I am an expert on high PH by now.... what do U expect with PH of 9+)
    Q
    In your chosen system (i.e. fish display pond + water garden) they will works on a very different set of ecological rules. A fish display pond equates to be like an indoor aquarium in reality. They are generally overstocked…..naturally their line of thinking will be to remove all the shits (ammonia concentration, low DO, disease & etc) ASAP and become priority NO 1. For those more serious pond-keepers they will want super clear view and I see so many inventions have been tried on to achieve this goal.

    On the other extreme of a garden pond….the solids (big or small) are integral part of the ecology system. Decaying materials are allowed to float and eventually sink to the bottom of the pond. The water column is usually tinted greenish cast and turbid. Well this is not dirty but represent the pond is alive, hahaha…..it is filled with bacterial and planktonic activities. Other wildlife…will also take up residence in this type of pond.

    A
    Yes green water is not bad in certain situations...except that it removes oxygen at night releases CO2 (good for U), and again the reverse during the day.....In low KH situation can cause PH crush....
    Heterotrophic Bacteria, plankton...worms... are a good additive to any filter... they help process the waste...
    U must remember that the increase of heterotrophic bacteria suppresses grouth of nitrozomas... and they need to be in balance. A filter goes through different stages of development until that balance is achieved, that is if u clean your filters regularly...
    Q
    Today, commercial mechanical filtrations are aplenty to choose from. IMHO, I would bravely conclude many of these filtrations work for rather a short time and not suitable in the long term…low maintenance operation outdoors consideration.

    Side note:
    I notice many pond-keepers have become obsessed with the notion of screening to the point where they start introducing super fine screens…..and naturally become enslave on a daily maintenance routine. Hehehe… OK. As long as they enjoy it…there is nothing to complain.

    A
    My izeki works like RDF...easy to clean and very cheap (low percentage shade cloth)
    Q
    Now the 3rd method is the most challenging task for many fish display pond to achieve its goal. They do not have the space and the volume that you have. As you see…we are actually introducing a recirculation system….many pond-keepers do not know how to take advantage of Mother Nature. Many just leave it to their contractor or pond builder.
    A
    Yes U are right...But I have seen proffesional koi keepers keep plants (barerooted) in their ponds for nitrate removal the "natural way"
    Q
    In a laminar flow, you will find solids denser than water leave suspension and drift to the side and bottom of the pond. The forces of gravity and friction cause this to happen. Your system can allow for an “In-pond settling” and it is very effective. You can actually plant dense rows of emergent plants near water inlet and outlet…which can be viewed as a vegetative screen. This vegetative screen reduces turbulence, enhance settling fine particles. As long as you provide basic aeration to the settle materials….it should not have deleterious effects.
    A
    Good in theory... but in practice plants are hard to maintain, they add to the polution in the pond... and hard to prevent anaerobic conditions... In short U are talking of veggy filter.. Media (planting) is very important.
    Q
    OK. Ok…I know, I know…by now many have more questions than you….hehehe…for example…..what is the appropriate size to have then for a given pond volume. The rule of thumbs is that to have around 15min water moving through the settling basin and this is estimated for a recirculation rate of at least once every 2 hours. Thus the size of this settling basin should be 1/8 of the total pond volume.
    A
    Ok. There will be some hardcore pond-keepers here which will want to have an example. Say, your pond volume is 48m3, then your settling basin volume should be 1/8*48= 6m3.
    Q
    Effectiveness of a settling basin can be improved by introducing incline baffler plates, incline tube settlers and the least efficient brushes. This basically will remove solid and to a large extent finer suspended solid by promoting fine particles to collide with each other to form a bigger lump ….thus settling by its own weight.
    A
    Baffler plates,TPR are normally introduced to increase the velocity of in pond flow...
    Q
    The challenging part will be removing the super fine suspended solid and currently, I believe the sand filtering method is the most practical and economical to have in the system. Many have reported the sand filtering will get blockage over times. I believe this is because in a gravity feed system, it is quite difficult to allow for a minimum of 1 bar (equal 10m of head) of water pressure for back washing. Therefore…deciding the numbers and size of the pump is very important.
    A
    I use both sand filter (special for Koi with swimming pool pump) and izeki on each pump...For the sand filter U need high pressure pump...maintenance not to hard since U attach a compressor to it...a small gadget to bring air into the manifold on the bottom and your SF is crystal clear in no time...
    But I still like my izeki better and get the same results...
    Q
    In your overall system….you will have the width and length to allow better settling design…. You can have this basin such that the side where the water enters, incorporate a baffle (if your flow is not laminar) to produces laminar flow and have the floor slopes upwards toward the end where the water exits. Install a purge valve at the deep end for flushing of accumulated material. You can refer to my 1st thread, page 6, where I have shown how I did the estimation.
    A
    Are U talking about onishi stream flow????? There is a better solution there...install air lifts on a timer and .... no waste in the system for too long...
    The floor normally slopes downwards in this design...not upwards towards the collection point...
    If I install collection point at the deep end where the water enters....????? where it will be the most turbulent flow....And how is the sediment going to travel against the current, towards the deep end where the water enters?????
    I am sure U made a expression mistake...the deep end is where the water exits and sediment collects...
    baffler will collect sediment....at a place where it is hard to clean...

    Check here I have googled it for U.http://www.google.co.za/webhp?sourceid=chrome-instant&ie=UTF-8&ion=1&nord=1#sclient=psy-ab&hl=en&nord=1&site=webhp&source=hp&q=onishi%20stream%20flow&pbx=1&oq=&aq=&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=4755da3e8d93f9c3&ion=1&biw=1366&bih=643&ion=1&pf=p&pdl=300
    Q
    May I ask….are you riding on the fact that plants take up ammonia as their primary food source?
    A
    Yes I do... and nitrates too...
    Now what U did not know and I mentioned above is this:
    Notice I want to be able to run them independently....
    notice the water gatden is the same size as koi pond....
    notice I am not talking/asking about filtration in the water garden....
    I want to conduct an experiment first, for the benefit of every one...me too...objective, independent opinion....properly conducted...and decide ones and for all if anoxic filtration works....
    If it does not work the filter is designed in such a way that....I can revert to normal filtration in no time.... But I want to know!
    And I want every one to know... for I dont like people spitting on something they have never tried , and some of them brainwashing us for commercial reasons...
    Can U imagine what a benefit that will be to every one????
    Minimal filter maintenance...
    100 fold reduced filter cost....
    and many more benefits...
    That I think can bring us to the nearest to natural filtration in a recirculating system...

    Q
    You need to watch out on the rate of vegetative filtration together with nitrifying bacteria in the pond. Plants (depending on the amount you introduce) can take up all the available ammonia especially if your fish stock is low. Ultimately…. you may need to fertilize your pond. Hehehe…
    A.
    U should look at aquaponics..... I did....
    I am posting a design for a pond...I think that is what U are talking about????
    image
    Post edited by Neli at 2011-11-10 05:50:30 am
  • NeliNeli November 2011
    Posts: 1,205
    Now can some one tell me the advantages of stream vs circular flow... since I dont get it.
    For me it is energy inefficient....
    The only advantage I see is That some people fear circular flow will bend their larger slower moving Koi... but I find that illogical..
  • harryyewharryyew November 2011
    Posts: 393
    Neli

    Oh!!! That is not good new. You need to go and see a doctor.

    Ok….now back to see where I can be of help.

    There are 3 basic equations you need to have. They are as follows:

    Hazen Williams Formula….. use the excel sheet I have posted.
    Good to know you have use C=150. You use this formula to calculate all the frictional losses (straight pipe length and the equivalent length of bend(25D) to the total straight pipe length that you have) in the piping works under a given flow.

    other major losses are as follows:

    Entrance loss at pipe inlet= 0.5v2/2g &
    Exit loss at pipe exit into barrel = v2/2g
    Exit loss at the weir of the pipe (1m vertical pipe edge) = 0.5v2/2g

    You total up all the energy losses.

    Continuity Equation … Q=VA
    This equation you use to calculate whenever there is a change in cross section area along the piping works to get your change in velocity. The Q (i.e Discharge along the pipe remain the same)

    Bernoulli’s equation: (P1) + mg(h1) + ½ m(v1)2 = (P2) + mg(h2) + ½ m(v2)2

    If there is only a slight different in elevation between the pond and the barrel small enough not to change the gravitation potential energy of the water much, you just ignore it. Many people get confuse what this P is. The pressure P is the pressure exerted in the fluid to cause the drawdown in your case.

    When a velocity is decrease as it flows from one point to another point, say water column v2 is now smaller than water column v1 (because of energy losses) and in order for Bernoulli’s equation to remain constant, P2 has to increase correspondingly to equal the left hand side of the equation. Now the drawdown effect is caused by P2 exerting onto the free water surface of the barrel to make the equation remain constant.

    In this explanation I have ignored the potential energy (mgh) considering there is a slight difference in elevation. When you reach the waterfall area…this (mgh) need to be calculated as the water pushed up to the height of the waterfall discharge.

    When a pump discharges a certain amount of water (flow) into the pond, it is exerting a pressure into it. This pressure we find hard to relate. It is as though it is coming from nowhere. In fact this pressure is from the flow discharging into the pond (kinetic energy) which goes into the BD. Some people when explaining name this as push head or propulsion head to drive the column of water from point A to point B.

    Hmm…..may be this simplification will be easier to understand:
    Consider the left side of the equation is for the pond side and the right side for the barrel side.

    Harry’s Equation: (z1) + (P1)/mg + (v1)2/2g = (z2) + (P2)/mg + (v2)2/2g

    This formula is still Bernoulli equation. I divide the Bernoulli’s equation throughout with a denominator (mg) to present with a diagram. Did you see the diagram in my earlier post?

    Oops…. I know where I have confused you. P/mg should be written as “y” and everything will fall into place as you only have elevation and velocity to take care in the equation. So sorry for my boo boo in my explanation.

    Thus New Harry’s equation:

    (z1) + (y1) + (v1)2/2g = (z2) + (y2) + (v2)2/2g

    This is the equation format you should be using to visualize and calculate the changes of the respective heads as you move from chamber to chamber and when you come to the waterfall or when there is a change in cross sectional area in the piping works.

    I re-attach here again a diagram to depict how the alphabetical values of the Harry’s equation are represented.

    image


    Quote:
    Now now now???? Tell me if I am "concludaring" correctly:
    Z1=Z2 P1/mg=P2/mg (we ignore head difference)
    Then I will have: (Z=25cm) 25cm + 170cm+2540(2)/2*9.81m/s2=??????
    (at Q=3000gph, V=77f/s=2540cm/s)

    Read the above and redo. Hehehe……..

    Quote:
    I just want U to see the links in 3 folders in my favorites that I have been battling with.

    They are useful and can be used to calculate.

    This one is confusing http://www.calctool.org/CALC/eng/civil/hazen-williams_g
    The computerize calculation for discharge and velocity work out has been modified to allow for situation where the pipe is slope to fall.

    Use the Hazen-Williams Excel sheet I have posted. It is easier to input the parameters to get our head loss and velocity in the piping works.

    Now… when you want to work out the discharge, velocity from the elevated chamber return via gravity flow.. then use Manning’s formula to calculate your average velocity. The roughness coefficient takes 0.009.

    These 5 equations should be enough to workout the hydraulic.

    Before I express further views on the other subject matters... I need to resolve my KH matter. Please share with me on this

    My pH reading is 7.9 and my KH value is 44.5ppm. Hydroxide alkalinity = 0, Carbonate alkalinity = 0, Bicarbonate alkalinity = 44.5ppm.
    To me this is not a god value to have. I was hoping for a value of around 120ppm. Is this a reasonable good value to have w.r.t the pH reading of 7.9?

    No, it is not because of the concrete in the new pond or water source. My pond is epoxy resin coated from main pond to all the filtering chambers.

    How many kg of oyster shells & coral I need to add for a 14m3 pond? What other solutions I should consider to bring the KH value up.


    Cheers
  • NeliNeli November 2011
    Posts: 1,205
    Hi Harry,
    Just came back from the doctor...
    There are 3 basic equations you need to have. They are as follows:

    Hazen Williams Formula….. use the excel sheet I have posted.
    Good to know you have use C=150. You use this formula to calculate all the frictional losses (straight pipe length and the equivalent length of bend(25D) to the total straight pipe length that you have) in the piping works under a given flow.

    other major losses are as follows:

    Entrance loss at pipe inlet= 0.5v2/2g &
    Exit loss at pipe exit into barrel = v2/2g
    Exit loss at the weir of the pipe (1m vertical pipe edge) = 0.5v2/2g

    You total up all the energy losses.

    Continuity Equation … Q=VA
    This equation you use to calculate whenever there is a change in cross section area along the piping works to get your change in velocity. The Q (i.e Discharge along the pipe remain the same)

    Bernoulli’s equation: (P1) + mg(h1) + ½ m(v1)2 = (P2) + mg(h2) + ½ m(v2)2

    If there is only a slight different in elevation between the pond and the barrel small enough not to change the gravitation potential energy of the water much, you just ignore it. Many people get confuse what this P is. The pressure P is the pressure exerted in the fluid to cause the drawdown in your case.

    When a velocity is decrease as it flows from one point to another point, say water column v2 is now smaller than water column v1 (because of energy losses) and in order for Bernoulli’s equation to remain constant, P2 has to increase correspondingly to equal the left hand side of the equation. Now the drawdown effect is caused by P2 exerting onto the free water surface of the barrel to make the equation remain constant.

    In this explanation I have ignored the potential energy (mgh) considering there is a slight difference in elevation. When you reach the waterfall area…this (mgh) need to be calculated as the water pushed up to the height of the waterfall discharge.

    When a pump discharges a certain amount of water (flow) into the pond, it is exerting a pressure into it. This pressure we find hard to relate. It is as though it is coming from nowhere. In fact this pressure is from the flow discharging into the pond (kinetic energy) which goes into the BD. Some people when explaining name this as push head or propulsion head to drive the column of water from point A to point B.

    Hmm…..may be this simplification will be easier to understand:
    Consider the left side of the equation is for the pond side and the right side for the barrel side.

    Harry’s Equation: (z1) + (P1)/mg + (v1)2/2g = (z2) + (P2)/mg + (v2)2/2g

    This formula is still Bernoulli equation. I divide the Bernoulli’s equation throughout with a denominator (mg) to present with a diagram. Did you see the diagram in my earlier post?

    Oops…. I know where I have confused you. P/mg should be written as “y” and everything will fall into place as you only have elevation and velocity to take care in the equation. So sorry for my boo boo in my explanation.

    Thus New Harry’s equation:

    (z1) + (y1) + (v1)2/2g = (z2) + (y2) + (v2)2/2g

    This is the equation format you should be using to visualize and calculate the changes of the respective heads as you move from chamber to chamber and when you come to the waterfall or when there is a change in cross sectional area in the piping works.

    I re-attach here again a diagram to depict how the alphabetical values of the Harry’s equation are represented.




    Quote:
    Now now now???? Tell me if I am "concludaring" correctly:
    Z1=Z2 P1/mg=P2/mg (we ignore head difference)
    Then I will have: (Z=25cm) 25cm + 170cm+2540(2)/2*9.81m/s2=??????
    (at Q=3000gph, V=77f/s=2540cm/s)

    Read the above and redo. Hehehe……..

    A
    Sorry Harry I made a diagram and I forgot to post it... Maybe U will understand better what I mean...My head is still buzzing. (I think it is not malaria.. I think it is from Harry's formula. He he he!)

    I understood it. But maybe I did not . this is the diagram I was supposed to post with my calculations:

    http://www.koianswers.com/discussion/download/4799/Harry'image
    Tell me if I am still wrong...????
    My z1 =z2 They will be the same level....Just e bend at each end...
    I said P1/mg =P2 /mg only if we ignore the head difference between pond and vortex.
    So my Z1=Zs+25cm
    P1/mg= 170cm (no?)
    V=2540 cm/sec (that is the flow velocity I want to have...???? (theoretical/hypothetical)
    Where did I go wrong????
    I understood U well. And that is the left side of the equation...I can only have differences in this case if I account for the head loss (no?) that is when I will get my P2/mg.
    But I understood the principle of it...
    Q
    Use the Hazen-Williams Excel sheet I have posted. It is easier to input the parameters to get our head loss and velocity in the piping works.
    A
    That one is the best for me and I thank U.I have some other calculators not very exact but gives a good approximation.

    Now… when you want to work out the discharge, velocity from the elevated chamber return via gravity flow.. then use Manning’s formula to calculate your average velocity. The roughness coefficient takes 0.009.

    A: I will need to work in reverse here...
    Q
    Before I express further views on the other subject matters... I need to resolve my KH matter. Please share with me on this

    My pH reading is 7.9 and my KH value is 44.5ppm. Hydroxide alkalinity = 0, Carbonate alkalinity = 0, Bicarbonate alkalinity = 44.5ppm.
    To me this is not a god value to have. I was hoping for a value of around 120ppm. Is this a reasonable good value to have w.r.t the pH reading of 7.9?
    PH reading of 7.9 is not high at all, ( PH up to 8 is best, up to 8.5 is not a problem at all)but your KH value is too low. U are right U need at list KH of 120 PPM to avoid the danger of PH crush... Some people give even a value of KH to be 200 ppm as best...????. All U have to do is put some shells in your filter or even bakki (he he he!) and U will be all right in the long run.. Not immediately.for short therm measure U will need to add some bicarbonate of soda...
    Or U can make a PH pill....very easy, and drop it in the filter.A friend of mine in SA makes them and sales them...
    I am sure U know that ammonia becomes more toxic in higher PH...
    The danger with pH is when rapid changes in pH occur, resulting in stress to your fish and, on many occasions, death. U should not allow changes in PH more than 0.3 within 24 hrs...
    Less is better.
    Remember if U have algae bloom U will have PH fluctuations during night and day... some time dangerous...
    Quote:
    I recommend that the pond pH be kept between 6.8 and 8.0. The lower limit (6.8) should be an early morning low, and the upper limit (8.0) should be a late afternoon high. But do not get too obsessive about this. If natural water conditions yield a pH of 6.5 to 8.3, leave it alone. Fooling with pH puts your fish in danger.
    Natural biological processes in the pond will tend to drive the pH down over time.
    LinK:http://www.fishchannel.com/setups/ponds/pond-water-quality.aspx

    Quote:

    Stability of Ph:
    Test the Ph of your tap or well water. Test the Ph of your pond. Make comparisons over a few days to establish what Ph your pond water should be on average. Pond Ph may be 7.0 to 9.0 but should be stable in a range of .3. If your pond tests at 7.5 it should maintain that level or similar to a low of 7.2 and a high of 7.8 over 24 to 48 hours. Ph crashes are generally caused by a low level of carbonate hardness. Carbonate hardness or Kh levels above 100 will prevent such Ph crashes and protect the health of your fish. Kh levels of 200 are required for bead filters.

    Stability of carbonate hardness (Kh):
    Carbonate Hardness = Total Alkalinity. Test the Kh of the tap or well water. Test the Kh of the pond. Make comparisons over a few days to establish your Kh average. Kh is the buffering ability of your water to hold the Ph at a safe level. Kh should test no less that 100. In the event of low Kh readings baking soda works exceedingly well to maintain proper levels, and can be added without fear of harming the fish. In addition crushed oyster shells or crushed coral can be bagged and placed in filters or in water current areas to buffer the water on a long term basis.

    One further note: If you have a bead filter in your filtration system, the Kh must be kept at 200 ppm or more for it to function properly.

    Baking soda: 2 to 3lbs per 1000 gallons will raise and stabilize Kh levels and keep the Ph at 8.3 to 8.4. Raise your Ph/Kh slowly over several days. Use maintenance doses of baking soda to keep them at a desired level.
    Link:http://www.simikoi.com/article7.html

    Quote:Koi can tolerate a higher pH far better than a low pH.
    I consulted Chris Nieves ( international expert) Who is a personal friend of mine (went to visit his house) And he advised me not to add any think in order to reduce My PH....9???? he just askedme about my KH....which is naturally high here. I have a borehole and lime deposits under...

    Q
    No, it is not because of the concrete in the new pond or water source. My pond is epoxy resin coated from main pond to all the filtering chambers.

    A
    source water????
    Q
    How many kg of oyster shells & coral I need to add for a 14m3 pond? What other solutions I should consider to bring the KH value up.
    Quote:+++++++++++++++++++++++++++++++++++++++++++++++++
    The next chemicals you may need to add to your pond are bicarbonate of soda and calcium carbonate. First, you must test your water for general hardness and for carbonate hardness. If these factors are not high enough, your pool may experience wide swings in PH (relative acidity to alkalinity) between day and night, due to the action of photosynthesis in your plants. Wide swings in PH can kill your fish. Thus, everything you do that can cause a change in your pond's PH must be done very slowly, if fish are already in it.
    Carbonate hardness should be above 90 parts per million. Increase carbonate hardness by adding sodium bicarbonate (Bicarbonate of soda) at the rate of 1 cup per 500 gallons daily until the desired carbonate hardness is achieved. General hardness should be above 150 parts per million. Increase general hardness by adding calcium carbonate or by making "PH Pills" out of Paris, mixed with water and allowed to harden in plastic tubs {like small cool whip containers} and placing them in your biofilter. (See Dr Johnsons "PH PILL" at
    http://www.koivet.com/a_phpill.html
    I have some very good publications but I have so many links that I can not find them now.
    I am looking...
    Quote:
    As the oyster shells top up the KH, they will begin to dissolve. Obviously when this happens, they’ll need to be replaced.
    So if U want it quicker dissolved U might want to crush it..then U will have better results from smaller quantities of oyster shell, and quicker...
    I dont know a dose for oyster shells...dissolution is a continuous process... so it will depend on many factors...size of particles for one...
    I was told to put it in the last chamber of the filter .
    Remember when your biological activity starts your bacteria consumes Ca, so your KH will be reduced further...
    I hope I was of some help....
    Post edited by Neli at 2011-11-10 11:19:03 am

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