Bunching onions, a squash, and watercress for now. The tanks have fish and the water gets passed though the gravel grow bed which filters the water and gives a place for bacteria to grow and thrive which keeps the water clean for the fish. The plants consume any nitrates left over after the bacteria do their job and everyone wins!
Oh the fish mostly handle that. Iv got a couple gold fish in the system that manage any smaller bugs.
Theres an aquaponics magazine though its not super active.