Nitrates and Phosphates

We haven't tried putting kent phosphate sponge in our reactors yet, but so far all of the phosphate remover's we've come across are more powdery than hard. I don't think size really matters as much as what it's made of. When you get thick, hard, abrasive nitrate stones in the same tube as a powdery phosphate remover, the phosphate remover will eventually get ground down. Nice try though!

Id just put the denitrate and carbon in the tube (2 parts denitrate for every 1 part carbon) and fill the tube about 3/4 of the way full since it needs some extra room for the media to float around.