Backyard Aquaponics
A place to discuss aquaponics

I know the standard 4:2:1 ratios but here is the situation. I have an opportunity to get a BIG above ground pool for almost nothing and I have room to put it inside a building. There's no way I could realistically see having enough GB capacity to sustain the standard ratios. Would it work ok by just lightly stocking the fish so the ratio of fish:GB stays at 4:1 or would I not be able to turn the water over fast enough to make nitrates?

I think the consensus is that the ratio is for near max stocking or feeding density. If you stock less, then less Grow bed volume should do.

If you can get your hands on the sand filter and pump with the pool, then that might help with your media volume issue and perhaps will make it possible to use some NFT troughs or something. I'm in process of installing the pump/filter from an above ground pool. I'm comming out of the pump and splitting off a feed to the grow beds before the filter and then going through the filter before feeding the water beds and bypass feed back to the pond/tank.

other options might include a fluidized sand bed which gives a lot of biofilter for the size.

So how big is really big?

Good luck with it!!!!

I don't have the exact dimensions yet but I believe it's going to be about 3000 gallons (11340L) It's a big one!!! I do think there is a pump but the filter I'm not sure about. Hey, I live in Florida. I should be able to build a sand filter with one of my barrels. My whole property is sand!! That should help!

You've got it. Stock according to the capacity of the filtration/growbeds. That will be your limiting factor. You probably won't have to worry about oxygen issues with the lower stocking rate. Your nitrates will probably stay very low, so plants that require less nutrient might do better for you. Take a look at some of the Member's Large Systems.

Go for it.

Thanks for all the great advice. I just got the dimensions on the pool. It's 9M diameter and almost 2M deep. I'm afraid I'll have to wait until a little smaller version comes available....

hmmm, 127000L

Have a look for the Pool Ponics thread

2m deep - harvesting would be a real fun event

Julie has that covered. wait for a really hot day then turn off all water flow and air bubblers

Could always try spear fishing in it.

Might not be so good for the pool though!

Steve: Julie has that covered. wait for a really hot day then turn off all water flow and air bubblers.

How does this help, Steve?

When the dissolved O2 level drops, the fish will come to the surface to gasp air, you can just net them out.

EDIT: Fish, not wish!

Any one with kids, have you read the story book "A Fish Wish" ? Watch out for fish in the pipes

Didn't KP have a nasty experience with that?

Poor goldfish.

Hmmm...fill it to maybe 5' deep....100k liters! 25k gallons! Wow! Let's see......tilapia are legal there....but they would overpopulate.....perhaps largemouth bass to keep them under control? Maybe a gator or some snappers.....but that would make it hard to take a dip on a hot day....

Gosh, this is more pond than tank. Yes, perhaps something smaller would be better. *grin*
Fun to contemplate.....