I voted refugium but in reality, I would not run a tank without both a sump and a refugium. I have never been a fan of canister filters in that they trap and hold far too much crap and unless you clean them constantly, you're never going to get good filtration. With a sump and refugium combo, you have more water volume, you can run filter pads in the sump to trap leftover food and detritus and the grasses in the refugium will "eat" the nitrates and phosphates out of your water. |