I failed utterly at aquaponics, not ever being able to set up a system that worked, after trying two different locations.  I could not even get the tanks level so the water would circulate without overflowing on one side.  So I have three big tanks (poly stock tanks) which have some minnows in them, along with one Egyptian Lotus and a bunch of Cattail plants.  Is there any good use I can make of these tanks without relying on circulating water amongst them?  I am thinking of selling them, but want to see if there might be a reason to keep them.

Establish a frog culture in them with azolla, duck weed and some other water plants. Feed the tad poles and azolla to your chickens

Collect rain water in them and use it later

Turn it upside down and use as a duck/chicken enclosure

Turn them into wicking beds (my favorite)

Burry them in soil and use them as root cellar

Turn it into a large worm farm

Those are all good suggestions, thank you!

You say that you could not get your tank level and it overflowed.  If at first you don't succeed have another go.  Aquaponics is easy to get very wrong but the fixes are usually simple.  We have a 3K litre round tub that was not full and a rain event popped out of the ground. We have it nearly level and put a stock trough filler at the lowest point running low pressure from a 126K litre water holding tank.  Use a small pump to pump water above the grow beds and let gravity do the rest.  put a layer of perlite or vermiculite over your growing medium and sprinkle seed over it.  Onions, lettuce, radish are a great proof of concept.  Add other seedlings in season.  Strawberries, and greens grow well.  Give it another shot.  Good luck.  I agree that a wicking garden is also good.  Do a bit more reading about aquaponics design Good Luck with it all.  Keep us updated

I have minnows in a water garden made from a cow stock tank. It's handy.

I water plants with it. Fill the chickens water with it. Grab a minnow to put in the cows (or horse, or sheeps) actual water trough if I see mosquito larvae.

If I buy minnows to fish, I can bring the rest back. Or I can take a few with me. It's 20 miles to nearest bait shop to buy them.

They are also good for raised bed gardens.  Someone mentioned a wicking bed. If it has a bottom drain, it's perfect for it.

I would suggest, since they already have cattails in them, using them in succession as a grey water marsh filtration system for your washing machine. This would allow you to also breed frogs and minnows and duckweed at the end tank where the water is purified. This lets you save/ recycle water that would otherwise go to waste for your garden. But do a little research as you may want/need to change your laundry soap.

Gurkan Yeniceri wrote:Turn them into wicking beds (my favorite)

Wicking beds are a great use.  I've done this with stock tanks and they work well.  One I grow lettuce in one and zucchini, beans or tomatoes in the other.