When you put in filter floss between the two media containers do you cover the hole up with the floss? I don't but I was thinking if you don't then maybe some crap goes back into the tank?
theres a hole from top to bottom in the compartments for waterflow .Inbetween the compartments u put filter cotton/floss in there, im sayin do cover the hole with the cotton since water flow will still beable to run through or plave the cotton around the hole