DC pumps are definitly the way to go, you wont need a valve on the return pump like you would on ac pumps. When you dial back the flow on an a pump you actually force the pump to work harder with the back pressure which will eventually take a toll on it (some pumps take alot longer than others) but all will make them draw more current. Eith a dc pump the co thriller actually slows to pump electrically by supplying less power to it to dial on your flow rate.
I also was having an issue with excessive heat in my tank, not to the point of a problem, but I noticed my heater was almost never coming on and my tank was reaching 80 degrees even during the winter and my chiller would actually turn on once in awhile. so I know something was up. After checking everything I found my skimmer pump(Ac powered sicce 1000) was getting about 95° on the surface... I took it apart and cleaned it and let it run and it was better but still too hot (85°) so the pump had to go. I bought a replacement and the temp was ambient meaning same as the water or air around it putting off no heat.
I actually just upgraded my whole sump and bought a new skimmer with a DC pump and honestly I wish I did sooner. It's so much quieter and so much more efficient and its 2x the size.
Hope this helps.
