Hi Guys,

I'm in the process of starting a new koi pond and would like to just run the design past the experts on the forum Any comments suggestions ext will be appreciated.
The pond essentially will have a total of 19,720 litters of water and approximately 1.0 meters below ground and 1.0 meters above ground. From the designs in this forum I would also like to include a window in the pond in one of the side walls.
The filtration part is designed to be gravity fed from a bottom drain to settlement chamber C1, Mechanical filter C2, Bio Filter C3 and last chamber for the pump C4.

The chamber volumes are 1,680 litters for the Settlement chamber 1,000l for the mechanical filter and the 3rd and 4th cambers are 500 litters each.

I will also be using 1 55w UV and 1 9w UV, still deciding on a pump but would prefer a low pressure submerged pump to save on Eskom bills. I'm also planning on running an airline into the Bio Filter as well as an airline to the centre of the pond on top of the bottom drain. Each chamber will also have its own drain and ball valve.
Please have a look at the design and let me know if the filtration will be adequate.
Thank you!
Willie

[You must be registered and logged in to see this image.]

Hi Willie

It looks like you did your homework.

Did you make provision for a skimmer box. Even if you have no trees in the vicinity, it is always good to have a skimmer and it helps a lot with water clarity and the prevention of solids falling into the water and sinking to the bottom.

I would have made my settlement chamber a bit smaller and the 500 liters chambers a bit larger.

You flush your settlement chamber normally more than your bio filter chambers, and each flush of your settlement chamber will cause you to add 1680 liters of water. Your space for bio filtration media might be too small.

Why do you have a ball valve in each chamber? Surely one in your settlement chamber should do the trick?

If you put two smaller windows in, you can get away with much thinner glass and save lot of costs.

Have you got bottom and mid returns? Always very helpful to get your solids to the bottom drain and it benefits the body shape of koi as they like to swim against the current.

Go for 110mm(or at least 75mm) waste pipes with valves in each chamber. It is frustrating to have 50mm drains.

I would definitely recommend a bakki shower to increase water clarity, bio filtration and oxygen and a way to de-gas Nitrates.

Keep us posted.

Hi Thanks for the reply.

Yes I have 3 returns Top, middle and bottom. I was thinking of adding a standard pool skimmer to the top return as that one will have the most pressure. The floating skimmer people use in pools are connected to the outlet of the pool. Saw one at chamberlains for around R500.

Thanks for the comment on the chambers, I will decreas the settlement and mechanical filter chamber sizes to see if I can get the bio filter to 700l filter. Will then aim for a 1000 liter setllement chamber which equates to around 5% of water volume. Will that be enough of a water changes every week, I was aiming for 10% but if 5% is good the settlement chamber can be smaller.

The valves on each chamber is to allow me to drain them seperately should it be required in the future.

Will see if I can get to 75mm drains, the 110mm valves are very expensive. But good suggestion.

I'll look into bakkie showers, I just think my space is a bit limited therefore for oxygen I opted for an airrated bio filter and air stones on top of the bottom drain.

I will keep you guys posted on progress over the next couple of months, we doing this one bit by bit!! Thanks allot!

Hi Guys,

Using the recomendations below I saw that I can make the settlement chamber smaller 1000x500x2000 which will give me 1000l in the settlement chamber. Chambers 2 and 3 can then be the same size and the last chamber smaller at 680x500x2000 will this be enough size for the filtration?

Still researching the bakkie shower to see how I can implement one in the design. Trying to stay with a low pressure design therefore I do not want to pump water to high above the pond level.

Thanks all!
Willie

Hi Willie. I agree with what Paul said, otherwise the design looks good to me. For pumps I suggest 2 airlifts. See this. [You must be registered and logged in to see this link.]

When calculating the size of your SC, U need to correlate it to the discharge of your pump, in order to allow particles to settle along the path of the water in the SC.
Minimum of 5 min detention time or 10 % of the flow is recommended for the size of the SC.

U can add some thing To slow down the water in the SC, in order to make it smaller...like brushes...netting like me,...plastic shavings like Kent Wallis USA, or pipe settler....
That is done to reduce the size of the SC, to economies on water usage...
Have U made provision for by pass when U are medicating?
Have U thought of calculating head losses...? The goodness of using a pipe is that U can always chop it down....just remember, if the level in your pond goes down....you will have limitation of the height of the pipe....between the chambers...and if the level of the pond goes bellow that, your filter chamber will dry and your pump will burn...
Think about that and think how to avoid it...that will happen only if U pump from the last chamber.
Easy way to make a spill way is to make a shallow channel, like a overflow into the SC, with a flap or just bricks to regulate direct the flow into the SC.
Remember U need circular flow in your pond, since your BD is in the center. One return will be enough, positioned in one corner of the pond...do not put your returns the way U have positioned them ...U need to put all of them above each other to spin the water around the BD, in order to have all the waste directed to it.
Look also where the wind is coming from, since it will contribute to moving the surface debris....and position your skimmer in the opposite side of the pond...water from the returns will also move the surface debris...so consider all that when positioning your skimmer.
Also don't forget to make the bottom of your filter chambers with slopping walls towards the drain, so that U can flush the dirt easier...
Have U thought of using sound pipes instead of gate valves?
All the best.

Hi Neli,

Thanks for all the replies!.

So understand correctly, I should calculate how much water there must be in the SC to allow the volume of water to be emptied in 5 minutes or more, therefore the water will be resting in the SC for 5 minutes.

Therefore for a 1000l SC and water to rest for 5 minutes the pump must not empty the SC in less than 5 minutes, with some math this is a 12000 l/h pump rate will empty the chamber in 5 minutes, therefore I should look into a pump of sy 10,000 l/h with a pond volume of approx 20,000 l this means the pump will then cycle the water in the pond around once every 2 hours.

For the medicating bypass I am not sure what to bypass? Could you please clarify.

For head losses the pipes will be 400mm below the surface, therefore the level of water should drop radically before the pump will run dry.

The overflow into the SC is an excellent suggestion - I will add one definatly.

On the returns, I actually thought of that yesterday All there will be in the corner next to the last chamber on top of each other.

I have never heard of Sound Pipes? could you please tell me more?

Airlift pump, I actually have a good industrial strength blower. I will research a bit and see if I can build a test airlift to lift water from my swimming pool hehe, If that works - you propably just saved me allot of money in buying a pump! Will let you guys also know how the expiriment is going hehe.

Thanks ALOT!

I really appreciate all these suggestions, I will only get to build this pond once so if I can get it right first time that will make me plenty happy!

Have an excellent day!

Hi Neli,

Thanks for all the replies!.

So understand correctly, I should calculate how much water there must be in the SC to allow the volume of water to be emptied in 5 minutes or more, therefore the water will be resting in the SC for 5 minutes.

Filtration retention time = Filtration volume/Discharge rate into pond 
That is for individual chamber or total filtration volume.

Therefore for a 1000l SC and water to rest for 5 minutes the pump must not empty the SC in less than 5 minutes, with some math this is a 12000 l/h pump rate will empty the chamber in 5 minutes, therefore I should look into a pump of sy 10,000 l/h with a pond volume of approx 20,000 l this means the pump will then cycle the water in the pond around once every 2 hours.

So for a pump that has capacity of 12000 l/h deduct friction losses, let's say U remain with 11000l/h
5m= V filtration/ 11000l/h
Vf=( 5 * 11000)/60= 55000/60= 9100liters....approximate that to 1000 liters
That U have to have if U don't use any settling additions.

For the medicating bypass I am not sure what to bypass? Could you please clarify.

There are some medicines that harm your bio filter, like PP, and some other...that kill your bacteria. So U need to bypass only your bio filter.

For head losses the pipes will be 400mm below the surface, therefore the level of water should drop radically before the pump will run dry.

I am also going to build a pond soon. So I decided to put my pipes in the filter in such a way, that I can avoid that from happening, by using the endless river principle of the erick filter...
The flow in the filter becomes horizontal and not diagonal, like in up and down filter.

The overflow into the SC is an excellent suggestion - I will add one definatly.


U need to calculate the flow of your weir...and remember in this case U will need to add automatic top up in the pond...something in the principle of toilet cistern...but for water tanks.
Water level in the pond is known to drop....so this way U can maintain your weir functioning all the time.
you can calculate the discharge or the height of the water spilling over a given weir length with many formulas.
A popular formula is Francis formula for the discharge of a sharp-crested rectangular weir having a length b greater than 3h is 
Q=3.33*(b -nh)/10*[(h+h0)(3/2)-h0(3/2)] 

where 
Q= discharge over weir, ft3/s (m3/s) 
b= length of weir, ft (m) 
h= vertical distance from level of crest of weir to water surface at point unaffected by weir drawdown (head on weir), ft (m) 
n= number of end contractions (0, 1, or 2) 
h0= head of velocity of approach 
If the sides of the weir are coincident with the sides of the approach channel, the weir is considered to be suppressed, and n=0. If both sides of the weir are far enough removed from the sides of the approach channel to permit free lateral approach of water, the weir is considered to be contracted, and n= 2. If one side is suppressed and one is contracted, n=1. 

Or use the easy one….Horizontal, sharp edged weirs (Bazins formula) 
Q = 0.66 x cB x (2g)0.66 x H1.5 
where; 
Q = water flow rate, m3/sec 
B = width of the weir, metres* 
c = discharge coefficient, average 0.62 
g = gravitational constant, 9.81 
H = Height of the water over the weir, measured behind the weir edge, m 
Here you can do the calculations 

[You must be registered and logged in to see this link.]


your discharge in the weir will depend on: Size of your pond (the difference in head between KP pond free surface water level and the drop of the weir crest free fall surface water level),area of weir discharge(L.H),and the discharge of your pumps. 


On the returns, I actually thought of that yesterday  All there will be in the corner next to the last chamber on top of each other.

I have never heard of Sound Pipes? could you please tell me more?


Sorry about sound pipes...it is stand pipes.

Airlift pump, I actually have a good industrial strength blower. I will research a bit and see if I can build a test airlift to lift water from my swimming pool hehe, If that works - you propably just saved me allot of money in buying a pump! Will let you guys also know how the expiriment is going hehe.

Blowers don't have the pressure needed for operating in depth, U are better off with a air pump...since if your filter is 1m deep, U will need to make the chamber for the airlift much deeper.
U will never regret going with the airlift option...it will save U more than R1000 a month in electricity. So make provision for both when building your pond, pump and air lift....and research the subject well.
Now most people are going with that option, if they want to economize...

Thanks ALOT!

I really appreciate all these suggestions, I will only get to build this pond once so if I can get it right first time that will make me plenty happy!


U need to have a look at a pipe settler...fantastic for a settlement chamber. Last year I saw some panels at the show, used for cooling towers, like a block looks like bee hive....I saw someone in Jbg using it as bio, but the real function for it is...settling chamber.
What happens is as the particles travel they conglomerate, and drop down the slop do the pipe. It allows U to reduce the size of your SC.
Another thing I would advise U to do is automate your pond...it will not cost much, but U will appreciate it in the long run....and easy way to do that is use air lifts on a timer...good for U but even better for your fish

Have an excellent day!

U are welcome. Glad to be of some help.

willieburger wrote:

The valves on each chamber is to allow me to drain them seperately should it be required in the future.

Yes, that is very important to be able to flush each chamber separately and each one must have a valve.

I thought you meant an auto top up inlet ball valve.

If you are limited with space, a bakki shower can always be around a corner away from your pond. If you see that the flow through your chambers are to high, you purely increase the flow to the bakki, and an extra 4000 l/hour pump with 2m head will do the trick and not add a lot of capital layout and running costs. Cheap plastic crates will suffice, especially if it is hidden away behind a corner.

Hi Admin,
Good idea!
I thought of putting a central 4" pipe under the chambers, with a T under Each chamber, with a standpipe in it....instead of valves...at the end of the long pipe also a stand pipe...for better security...
What do U think about that?

I forgot to tell U why u need to calculate the discharge of your weir. The weir will reduce the flow through your bottom drain pipe. U need not to reduce it too much, or you might have pipe blockage.
Make some flap that U can tilt, and regulate the flow of the weir, or be able to close it completely when flushing the BD pipes.

Thanks Neli!

Lots more research to do! Appreciate every bit of info!

Willie

Hi Willie.
Airlift pumps are really easy to build but you will see once you start playing with it a little. Look at the video links I posted.

Hi Neli, You do not possibly know if there is an off the shelf weirs that I can buy with the flap? The standard swimming pool one comes to mind although the flow will be to much even with the flap. If not I will make something out of wood and build it into the wall, would just prefer plastic.

Then on the airlift, I played yesterday with my blower. I have a 70 old industrial blower and managed to lift the water with a 50mm pipe in the pool. Not the most effecient, but the blower works great and produces a large amount of bullbles at +/- 1.8m (in my pool) Will still be experimenting with 75mm and 110mm pipe to see what flow rates I can get with the blower. But I think your idea just safed me from buying a water pump! THANKS!

Have a great day all!

Willie

willieburger wrote:

Hi Neli, You do not possibly know if there is an off the shelf weirs that I can buy with the flap? The standard swimming pool one comes to mind although the flow will be to much even with the flap. If not I will make something out of wood and build it into the wall, would just prefer plastic.

Then on the airlift, I played yesterday with my blower. I have a 70 old industrial blower and managed to lift the water with a 50mm pipe in the pool. Not the most effecient, but the blower works great and produces a large amount of bullbles at +/- 1.8m (in my pool) Will still be experimenting with 75mm and 110mm pipe to see what flow rates I can get with the blower. But I think your idea just safed me from buying a water pump! THANKS!

Have a great day all!

Willie

Hi Willie,
I don't know of any flap ready made for sale. My friend uses two bricks, that he puts in different configuration and it works well. But I am sure U can make it from stainless steel. With hinges on the bottom, and put a brick behind to hold it or put a wheel behind, eccentric one, that U can rotate and adjust the flap. 
The bigger the pipe for the airlift the more flow U will have. U need 110mm+ pipe, and U need to make a manifold on the bottom. I wanted to use two sewerage fittings which have one side 110 and the other side much larger,looks like a reducer to 110 , glue the larger part together, connect the air line to it, and put inside a 110 pipe with slots.
Think of something in those lines.look at Tommy's links...u will figure it out.
Another advantage of air pump is that is very low wattage, and saves U more on electricity than the blower.
In this day and age, I would not go with a pump...air lifts will work fine with your pond. Just make one deep chamber at the end of your filter, and the rest is easy!
Wish U all the best, and if U have any questions let me know.

willieburger wrote:

Hi Neli, You do not possibly know if there is an off the shelf weirs that I can buy with the flap? The standard swimming pool one comes to mind although the flow will be to much even with the flap. If not I will make something out of wood and build it into the wall, would just prefer plastic.

I have always used the swimming pool skimmers. They are cheap and you should have a valve on that line in any case to manipulate the flow.

Never use wood. It will not last, it will leak, and it creates a breeding ground for bad bacteria.

Thanks Neli and Admin!

You've been a great help! Really! I cant wait to put some pictures up of the end product but yes digging starts this weekend

Willie

Hi Willie

Come visit us at the Koi Show this weekend at the Bright Water Commons in Randburg, the old Waterfront.

You may just get some good ideas and equipment there.

Neli wrote:

Hi Admin,
Good idea!
I thought of putting a central 4" pipe under the chambers, with a T under Each chamber, with a standpipe in it....instead of valves...at the end of the long pipe also a stand pipe...for better security...
What do U think about that?

Standpipes instead of valves work well. This is how I do my settlement chambers:

[You must be registered and logged in to see this image.]

Obviously you still need valves on the waste of each chamber to flush.

Admin,
U don't need valves if U use stand pipes inside the chambers...valves for 4" pipes are just too expensive...
The think to keep in mind is to put the strong end of a fitting where the stand pipe will enter all the time, so that it does last a long time.

The thing with stand pipes is that they break the fittings after some time and to replace a fitting thats in a concrete floor is not a joke and keeps on giving you trouble. Even if you use the strong end of the fitting. Valves will be better. Short term solution is stand pipes until you can install valves. You also get leakage from standpipes and I find it a little risky to use them.

Hi Nevil, Neli

I wish I could visit the Koi SHOW but I am in Durban this weekend.

I will see maybe sunday afternoon I can make it.

Will try my best!

Hi Guys,

Neli was right, the air blower just does not have enough uhmf to get the air down to two meters, the bubbels stopped at around 600mm and the flow rate through the 110mm pipe was very low

Any ideas of good air pumps that would get the job done, 110mm lifted 2m and looking for a flow of 10,000L ph

Thanks

The cheap air pumps capable of pushing to that depth will be the Boyu ACQ-009, 009A or 012. They start in the region of R 900. They can pump to a depth of 4m but the problem with them is that their piston and sleeve wears out over time and you loose pressure. It will last about 2 years if ran constantly. Ive had several 3 x 003, 2 x 005, 3 x 008 and 1 x 009 that is since 2007 although not for the same application. They also become noisy after a year or so and start to jump and vibrate around. The smaller pumps 005 and below vibrate from day one. [You must be registered and logged in to see this link.]

The better option would be to go for a diaphragm pump like a water fall or Hi-blow, they dont have the pressure of a piston air pump and its important to look at the graph that shows air delivery at depth. They will deliver very happily to a depth of 2.5m, they are more expensive starting at around R 2000 but they are cheaper to maintain and have cheaper running cost. The most important thing about these pumps are to make sure you will be able to get diaphragm in a year or two cause if you cant replace the diaphragm the pump is useless. Dont go with odd brands here - you can burn yourself also keep in mind that these pumps are imported and the dealers are always changing what they stock so you might have to import the diaphragm in a year or two.

Thanks Wayne!