Hi. The general rule for gallons per hour is 4-5. So for a 55 gallon aquarium that would mean 220-275 gallons per hour. If your filter can do this then you will be in good shape. If it can do more, that's even better as long as the current isn't too strong. Once you fill your aquarium with rocks, gravel and decorations you'll displace some water anyway so that'll drop the amount of water in your tank probably to somewhere in the high 40s gallons. I use a Penguin 350 on my tank and it does a great job and as said above it has 2 filter pads, with room for 2 more so you can change one at a time if you like, and the bio-wheels never get changed.