Benjamin Slade wrote:

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

I have one of these that I use for tank cleanup. The motor is a sealed unit at
the bottom of the filter. The impeller is magnetic drive. It'll put about as
much heat into the water as any cannister filter of a similar size.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.