I have a 75gl tank with a 20gl sump that is sectioned off into three parts. In the first part (starting from left to right) I have some live rock,glass bottom, and that's where the water from the tank comes into the sump. In the middle part I have 3in of sump mud, that I have to change, Some cheato, crab, small peices of live rock and some plants, In the final section I have 2 small peice's of live rock and the pump that pump's water back up. Is there anything else I need. I'm taking my canister filter out today because I think it might be causing problems.