I have been doing aquaponics for about 4 years I currently have about 6 24" trout and a couple of small silver perch in my other system. I have a 1000L IBC for the tank and 3 gro-beds for a growing area of about 4.5 m.
After a while the system balances out and will grow most things, I have grown, lettuce
, beetroot, cerleriac, celery, basil, carrots, tomatoes, silverbeet, cabbage, broccoli, beans, parsnip, swede, watercress, snow peas, peas, cucumber, I even grew sweet corn once, there is probably more but I forget.
To balance the system and prevent many deficiency problems I add an occasional dose of seasol, I also make sure I have worms in the grow-beds as they help chelate the minerals and provide a better balanced system.
Over time the beds can tend to become a bit acidic but this can be adjusted by putting shell-grit in the system.
Be prepared to sometimes lose some fish, disease and system failure will occasionally happen, and you have to have backup systems to keep the pumps going and the oxygen to the fish during power outs.
The power company is shutting our power down for maintenance work on Tuesday for 8 hrs :angry:. If I did not have a generator I would lose all the fish.
It's interesting and if you want the fish probably worth doing, if you only want veggies I would look at wicking beds they provide many of the benefits of aquaponics especially in water efficiency.
Some people have also experimented with flood and drain worm fed systems where you put vegetable food scraps in with worms for the nutrients and spread them via flood and drain. I am not sure how well it worked.