Some info on my project first. I have a 37g tall tank and I'm not sure how I want to filter. I want to(scratch) need to save money, I have a second child coming any day now. I want to put the tank in our bedroom, because there is plenty of room and no where else in the house does it seem to work. So, I have been debating on getting a HOB or getting a canister. Noise would be a factor and have leaned to the canister for simply can hide it under the tank and want to keep the tank as close the wall as possible. I like the Rena XP2 or a Marineland Penguin 350. So, Advantages of one versus the other? Also what would the cost factors be. I'm using this tank as a stepping stone to Saltware down the road when the kids our out of college. Have plenty of time to prepare.