Alright, I recently switched everything in my 55 to a 75 and the 75 has had a stink to it starting about a week after the switch. I have actually reduced the stock and added filtration (FX-5 and 305, and pothos) but it doesn't go away even with water changes. The parameters are good and he filters are mature but it still smells like a greenhouse in my office (room where the tank is). That is really the best description I can give of the smell, just like a greenhouse. Any ideas on how to fix this? Would carbon do it?