I currently have a 55 gallon tank with an aqua clear 70, but latley the tank water has not been as clear, I have been told since it is a 55 long, a hob filter is no good and a caniser filter is what i need. However the gentelman i was talking to couldnt tell me why. So I was wondering if someone on here could tell me why a canister filter is better. And if a fluval 404 would work as I am trying to get one of of craigslist.