thermometer in sump

[newfishguy]

I have a 20 gallon sump below my tank with a skimmer and mag7 return pump. Should I just keep my heater in the sump instead of the main tank? I just got my RO system yesterday and have yet to put water in the tank. However, shouldn't there be a consistent overflow of my tank water into the sump and a return of heated water from the sump? This should keep the water in the main tank heated since it will be constantly cycled through the pump, right?

 

[trainfever]

Yes, put your heater in the sump. The water will be heated in the sump and pumped into your main system. I have a digital thermometer in both my sump and my main tank and there is no temperature difference at all, not even a tenth of a degree.