I took the advice of those here and got the rena xp3 for my new 72 gal BF. Found it at Al's online for $90! (there's a link on my post -- HOB vs canister) We also got a 300 watt rena smartheater (petsmart, but found it cheaper online after the fact -- it replaces the water intake and heats it before it goes through the filter -- pretty cool! doesn't look like it, but really don't know if it is affecting water flow...). Too soon to give a report, but no complaints so far...