Backyard Aquaponics
A place to discuss aquaponics

About 5 gallons of water per full size fish. My minnows can live in 1 per liter and you could eat them if you wanted too. Can you get any local fish? They are accustomed to the weather you have. We go out and collect our own. All of them come out of ice cold streams, even 1 blue tilapia baby so far.

Hi GT2016

Trout might be tricky in your small system. You're probably not going to be able to raise any fish or crustaceans big enough to give you a feed. Might be best off going with goldfish. They're pretty tough and can handle a good range of temperatures.

In addition to Deuem's advice above, your wet media volume is probably the most relevant measure of stocking rate... rule of thumb being 20 - 30 L of wet media for each fish that you intend to grow to plate size. If you use goldfish, you might be able to squeeze a couple more in... although I hear that they produce lots of waste so be cautious.

You'll find the clay balls (might be called hydroton) in most, if not all, specialist hydroponics shops.

Have a look at Gunagulla's thread wrt the solar stuff... viewtopic.php?f=18&t=16345 it's more than 50 pages long so you might have to use the search tool... although there's heaps of useful stuff if you have time to read the whole thing.

Good luck.

As far as I know, Gold fish are first on the list of fish that pee. 2/3rds of their body weight per day. They also poop non stop. They can take cold water if it is a slow change. The carp I have can live under ice if need be. Koi are nice for a small tank if you can get babies. Just remember which fish will grow up to be monsters. In your 25L tank I could put 25 to 50 minnows depending on the filtration and air. I have that many in a 10 L now. (all babies we catch) It produces 3 liters of usable prepped water a week. As soon as I get some more of these 10L glass jugs I plan on topping them with Net Cups and making mini AP Units with Air Water lifts thru the cups.