So I have a planted tank already . It's just black sanda I've had poor performance with plants mostly stems. I'm looking to try a low tech planted tank with flourite black on my 60l just as a tester and if everything goes well transition it into my 140l. I want more of an understand of how it works . I understand that it works like a cec . It has some nutrients within the clay substrate but I'm guessing it takes nutrients from the water column and stores them in the clay granuals and releases them when need be ? So fish waste / left over food will break down into the nitrogen cycle and be absorbed into the gravelfor the plants ? Is this right ? Also I hear you don't need to cap it ? Thanks.