Cool, ty, I was reading posts and didnt know if it was chaeto or calepuria. Is he correct in that it repalces the bio balls? From what I am reading and I could be confused, it only effects the Nitrate leves and does not do anything to break down ammonia.
Seperate topic... I am assembling a 90 gal, its a huge step up from the 29 with a hang on filter and no skimmer. I am lookign to build a sump but am very very confused. What is the difference between a sump and a refeguem? (sp). And is there something different then a wet/dry?