Question

Do fish and plants need to be separated?

Community Answer

Yes and no. The reason for the grow bed in this design, is not only to help remove the solid fish waste from the water, but to also give a surface for bacteria to colonize and convert the ammonia into nitrogen for the plants to feed on. Without it, you will need to perform regular water changes, which defeats the purpose of the system. You could use a second tank as a deep water culture if you wanted. Simply have the water drain out of the filter media into the second tank at one end, and drain back into the primary fish tank from the other. In this tank store a hardy shrimp species, and they'll happily clean the roots for you.