Skimmer pump question

[buildinboats]

Sorry for being a little out of touch with current skimmer technology. Do all of the skimmers I see (Deltec, MRC, etc.) with what look like powerheads mounted externally to recirculate and aerate the water inside the skimmer require the powerhead to be submerged in a sump for cooling?

The reason I ask is I would like to upgrade my DIY skimmer and get rid of the airstones but do not have the option of placing the skimmer in a sump.

 

[buildinboats]

bump

 

[klam114]

For needlewheel pumps, no, they do not need to submerged. In fact, that's what so nice about them in that being that they don't need to touch water, it transfers less heat into the water.