Filters are fine. I would guess you had enough flow, but that may be debatable. Most things say 2-3 watts per gallon for heaters, but that rating depends on how close the temp of the room is to the temp you want the water to be.
Had enough flow from 2-2213s, even on the 40. Each filter would turnover the water in a 40 2.5 times a hour. 5 times water turnover is more than adequate for any tank. Easy to attain that with smaller tanks.