Hello. I am new to this forum and appreciate all the help you can give. I am currently in the planning stages of my new koi pond. It will be small pond and I most likely will only have 23 koi. My plan is for around 1500-1800the and somewhere around 10'x7'x3-4'. I plan on incorporating a bottom drain to a settlement tank (diy). I am having trouble deciding on either a 3" or 4" pipe to settlement tank. I also plan on th bottom third of the tank being empty ( no media) and then the next section having some kind of media. I will put a smaller valve for cleanoit of the bottom chamber but am very confused on how to pull water out of settement tank to the waterfall filter. I was wondering if a submersible pump could sit in top chamber of settlement tank or does it have to be separate. If i could put pump in the top of the settlement tank it would make my life alot easier. Oh yeah, my settlement tank will be gravity fed. Am i way off with this concept? Thank you for all your help.

bsean0714,

Firstly the size of the pond that you are planning is too small to accommodate 23 koi. I would build the pond at least 23 000 l to accommodate the 23 koi you are planning to keep, however most people would consider this as over stocked.

I would not use anything smaller than a 110 mm class 6 pipe from the bottom drain to the settlement chamber.

I would also not build only one chamber and pump from the same chamber as this will not allow the waste to settle unless this chamber in very large but still I would recommend a second chamber with filter media and to pump from.

I apologize. I meant 2-3 koi. How far below the water level should I put my outlet bulkheads to the next chamber?

Approximately 150 - 200 mm below your water level should do.

Ok so should the first barrel be completely empty (no media)and and then overflows to second barrell that is divided into sections for media and submersible pump? Then pump to waterfall filter? Thank you for all your help.

No, it is advisable to have something to collect the waste that does not settle and you want to avoid it from flowing into the second chamber.

Have a look at my post under equipment were I have used a sieve basket to collect heavy waste, this should help you.

Sean
U must remeber It is always mechanical filtration first and then bio...no dirty water should enter your bio, or it will not function properly.
So I would Use the first drum as a vortex...with a possibility to add brushes in it.
Then I would have another drum gravity fed from the first one with some media, to remove the finer particles, before the bio drum.
For media U can use many DIY materials depending on Your budget.
U must remember head losses...so U make provision for that.
have U made provision for a skimmer?
I presume U will make your SC water level the same as your pond level. I personally will use external pump. U can pump from the SC to the rest of your filters, and incorporate one of the drums in the water fall, like ERZ. But I would use 2 drums..if possible. But for such a small pond I guess 2 can do. How deep will U make your pond? Whay not make it a bit bigger...it will not be much of a difference in cost and U will not feel sorry later.How deep will U make it? I have shallow pond and it affects the skin quality of my fish. UV light is not too good for them.
U can also make a overspill DIY as a skimmer by incorporating a pipe in the pond that can tilt. Many people use that.
Post some pictures of your design, area where U want to put the pond...we shall try and help.

I will post for U some pictures of my DIY filtration this evening. It is made from drums, and I use it for my QT which is 7000liters.

Ok, so my plan is to now use a two barrell design with the first being a vortex with brushes and second containing some sort of media and the pump, pumping water to water fall bio filter. What kind of media should i use in second chamber and what size and how many oveeflowline pipes to thecover second barrell. Also, what size pump should i consider for thethe second barrell with 4"pipe bottom drain? Any ideas on how to partition the barrells dor the sections of media? Thank you for al your help.

bsean0714 wrote:

Ok, so my plan is to now use a two barrell design with the first being a vortex with brushes and second containing some sort of media and the pump, pumping water to water fall bio filter. What kind of media should i use in second chamber and what size and how many oveeflowline pipes to thecover second barrell. Also, what size pump should i consider for thethe second barrell with 4"pipe bottom drain? Any ideas on how to partition the barrells dor the sections of media? Thank you for al your help.

U will have to put the first two drums level with the pond and feed them by gravity. I used this special expensive suction pipe, instead of rigid pipes...It is flexible, and it is much easier to use.
You will need to pump as U said from the bio filter...to the water fall.
For media in the vortex, is good U decided on brushes. I use garden shade cloth with large holes, and designed it in such a way that it is easy to clean. It is also long lasting and cheap.
Remember U will need to spin the water in the vortex, so put the inlet pipe with a bent inside, 20-30 cm above the bottom of the drum. There is another system to use as a vortex prefilter very easy to use designed by Kent Wallis USA...It is a plastic bucket inside the drum , with lots of holes, with a exit pipe inside also with lots of holes...filled with plastic shavings to prefilter the water. So the water also spins around the Bucket and solids are deposited on the bottom, but is prefiltered also by the plastic shaving before it goes to the bio filter.
Dont forget to put a drain in each drum on the bottom. How Will U drain your drums if they are bellow soil level? Is your pond going to be partially above ground level...if U do that U can use the flexible or rigid pipe to bring your waste above ground but bellow water level...at list 30 cm, or make a sump to drain the drums.
U Must remember that if your drums feed by gravity and the pump is sucking from them...if the level in the pond goes bellow the outlet pipe of the drums, your pump will not be fed and run dry.
Have U thought about that?
I pump directly from a perforated pipe on the bottom, to a Birdman sand filter, and then by gravity to bio and pond.
I have seen some float valves...for large tanks...that operate mechanically...open when the water level goes down... Maybe U can incorporate one for a safety measure in the last chamber...so if the water in the last drum goes bellow your pipe...it opens and brings water for the pump not to run dry.
What is going to filter the fines in your pond?
Brushes are not very good for that...if U want clear water U need to have something to filter the fines.
U can Use the media in your biofilter, but that is not advisable...it will disturb your bacteria.
Maybe U use Kent wallis pre filter...(the bucket)
I can send U pictures if U want.
U dont need overflow pipes if your drum is gravity fed...but if U get obstruction in one of your barrels, U will need that float safety valve...
If U mean pipes for the water flow between the drums...This is what I think.
your pond is around 1800 liters...to have a turn over rate of one hour...U need a pump of 1800 liters per hour.
2000 liters passes very easily by gravity through a 2" pipe...so Regardless of your bottom drain being 4" ( U dont need such a big BD for your pond) 3" is more than enough.....so if U use 2" pipes between your drums it will be fine with that size pump.
It depends on your budget what media U will use for your bio...best is K1...aerated...in the drum...will do wonders...but it is also the most expensive.

Also remember...2000 liters Water flow will not give U much water for the water fall...so design it in such a way so achieve maximum effect with the amount of water U have.
Dont make the weir to large...or make it run over stones...

I think pvc would be fine for my application howvever i could see the benefit from the flex pipe u speak of. Is it necessary to use pressure pipe or will schedule 40 terrain pipe work?

i AM not too sure of schedule 40 pipes...I have only two types here. blue and white...
The blue one is the better one and that is what I use.
U will not have much pressure in your pipe...but the blue is longer lasting... and if U have to bury the pipes...U can have external pressure.
For the flexy pipes...I meant to use them only between the drums.