One of the reasons I don't have a sump is for space and leak prevention
reasons. So for those reasons, I'm not really excited about a filter
canister on the floor.

Hmmm, maybe a hang-off-the-back canister filter like:

http://www.aquariumguys.com/magnumfilter2.html

Except I would be using it without the filters, just to move water. I
know thes seems like sort of a silly way to move water around, but if it
keeps the tank cooler, it's useful.

I wonder if the pump in this type of canister filter is water cooled, or
air cooled?

Ben Slade
Washington DC

Rick wrote:
Why dont you run a canister filter? Ehiems have a good output
efficent enough for a 40 gal tank. I had one with my 55 gal used it
along with the life rock