I have a filter on a fish tank with perlite and activated charcoal as a filter...so I put in a clone, and it grew... I am not with clear mind at this moment...but the carbon filters out micro things.... roots take up micro things... so to speak... if I fill a pot with activated charcoal(carbon) and planted the clone, ran normal nutes... what happens?
I tried growing a seedling in filter carbon to see if I could find a use for it and it didn't go well, but it was because the watering schedule was wrong. If you are running water through it constantly it should be fine
I would say 50 gph runs though it. My only problem I see right now is my fish load is small, and fairly new. The clone is growing but maybe a little slower than norm. I also root clones is this tank with great luck! Thinking maybe my mother will sit on top my tank and feed on fish waste, they always grow to damn fast anyways.....???