How much water is too much?

[Rob Nash]

I have a koi pond that is aproximately 6000 gallons, and want to connect some flood and drain beds to it. I dont have room to add the normal ratio of grow beds,which would be about 1500 sft,  but can do 200 sft. The question is... why not just stock the fish at the 200 sft ratio, and size the pump accordingly?

So im thinking, treat it like an 800 gallon system... 2500 gph pump, 200 sft of grow beds, and no more than 400 lbs of fish.

im looking for feedback?  TC, Vlad, any thoughts?

PS- the pond in this picture is not the one in question, this is yet another pond that we plan to connect to a raft system.

[Rob Nash]

[Vlad Jovanovic]

I think TC or someone else would be better fielding this one... 

Seems reasonable though IMO, to stock according to bio-filtration capacity (business as usual)...

Where peoples opinions may (or may not) differ or where it may get 'tricky' is the 'turning over the water volume once an hour' "general rule of thumb"... It seems pretty extreme (and at first 'glance at least...probably unnecessary) to be turning over 6000 gallons of water an hour because of 400lbs of fish... General rules like that are 'generally' not carved in stone and are just good 'general' practice and may not be particularly necessary in every situation...Probably a 'generality' that comes to us from the world of RAS or aquaria...

But again, I think you'd be better off going with TC's or someone who has some directly related first-hand experience relevant with such a scenario... 

[Jeremy K]

I use my koi pond to power my grow beds. I have what once was a diving pool with about 100 koi. I pump that water at 2150gph though a series of filters, 55 gallon swirl x2(I split the flow because it was to fast to settle out the solids) each flows in to another 55gallon drum with coarse media and then into another 55 gallon drum with finer media, then into 2 55 gallon drums with lava rock as a bio filter. From there all the water runs in a 6" PVC pipe to 4 330 gallon ibc tote gardens into the tank, the tanks have a 264gph pump pumping the water from their tanks into the grow beds. The tanks have overflows on them so the excess water can pour back into the pool. I believe my pool is 16,000 gallons and my grow bed sq/ft is about 48. It has been running like this for about 5 months now and the garden loves it and the pond water is green but clear to the bottom of the shallow end. Oh yeah I have a 110L an hour air pump aerating the pond running 1 six in round air stone, and 2 four inch round air stones. The stir sediment up that the pump to the swirl filter grabs and sends though the system. If I turn the air pump off the pond will settle and I will be able to see the bottom of the deep end 8.5ft

[TCLynx]

No matter what you are doing you should only ever stock to the level of your filtration/aeration/circulation.

Now if it is an existing koi pond, I expect there is already some filtration and enough circulation to keep the water nice.  So why not test the water and see if there is any nitrate reading to support growing some veggies.  A koi pond with filtration is probably already cycled up to it's current load so all you need to do is sort out flow to the grow beds and back to the koi pond and it will simply provide more filtration.  Then if you find there isn't enough nutrient for your veggies, you may be able to add more fish (keep in mind that you may need to supplement aeration as you add more fish.)

[Rob Nash]

thanks everyone ...i will keep you posted on the results.    this is going to be an awesome build!

im consistently blown away by the number of folks wanting to go large with AP. im in Central Texas ...not known for being "farm country" at all, yet there are at least 6 commercial operations in the area... that i know of.      

...sounds like a good local for the next AA conference.