cool running pumps

[thebatcave]

I would just like to get a few opinions on a problem that I've been having for a long time. The return pump from my wet/dry creates a lot of heat. I originaly had a Quite One Pump, but decided to try a different brand because it heated my water too much. I bought a Mac 4 Pump, but it also produced a lot of heat to the water. I'm back to using my old Quite One Pump due to that the other pump is getting tuned up. The thermal overload protection keeps turning on and off the pump on the Quite One.
My question is which pumps can produce about the same gph but with minimal heat transfer?
thanks

 

[jimi]

I recently replaced my dolphin pump with an iwaki. It is by far the coolest pump I have ever had or seen. It is actually cool to the touch I think it has a built in fan that runs with the motor constantly.