I have been using fluval canisters for years with no problem. The way I treat the canister is like a sump. There are no pads inside to collect food/poo. The only thing inside is a (2)bag of BRS Rox carbon and Matrix biomedia. I replace the (1) carbon bag per month.
I placed attached a CPR overflow box in the tank. Inside the box I placed a light grate to float in the middle. On top of the grate I place felt to act as a filter sock. The debris is trapped there and not in the canister. The filter pad is easily changed ever other day. I have the canister intake and the hob skimmer intake also inside the overflow box
I placed attached a CPR overflow box in the tank. Inside the box I placed a light grate to float in the middle. On top of the grate I place felt to act as a filter sock. The debris is trapped there and not in the canister. The filter pad is easily changed ever other day. I have the canister intake and the hob skimmer intake also inside the overflow box