MJ CANNOT grow submerged, it just doesn't have the anatomy to do that. however, your friedn was probably talking about those novelty plant/goldfish things you can buy, where it is a plant fed by a goldfish in the water below. Works on a small scale, though not well. You could do the math and figure out howmuch emulsion fish are giving off, and try and balance that with how much oxygen both the fish and the roots need, but it is way easier to look at on of Organics threads about soils. With some of his mixes you never have to fertilize. And even if you need to, it's not much and practically idiot-proof. (knock on wood)
