I personally like to have at least twice the rated gallons for my filter so like Fajita said, one rated for more gallons would be better. I like to have 2 filters on my tanks if I can just to "make sure" in case one dies or something unexpectedly gets clogged. I have two canister filters on my 55 gallon, each rated for 100 gallons. I have not seen a huge difference between HOB's and other filters I just think go for more filtration.