Ok, so my tank is about done cycling. I have LOTS of snails now. I have a penguin350 HOB. I've noticed a scummy looking coating on the outflow of the filter. Should I leave it alone, or clean it off?
I would lightly scrub it off. I received a tank with a filter that had been clogged from so much algae. If you don't clean it eventually it will become worse. Your filter media and what not will have enough bacteria and stuff in it. I guess it also depends if you want a cleaner looking tank or not. However i don't think it will affect your water chemistry much.