i have a 5'x2'x2' and i was wondering if i can get away with using a canister filter system, i noticed that a lot of people use sumps on these size tanks but i really don't want to use one so i was wondering will i be ok without one.
A sump with wet/dry isn't necessary for big tanks. Just becomes more practical the larger the tank. I wouldn't want to deal with 3-4 canisters on a huge tank, but I've heard of it being done. You can certainly get away with 2 on a 125. A lot depends on what you're stocking, but I'll assume you're like most of us and it'll be a full tank.