I noticed that when my return pump is running, my system experiences a temperature swing from 73 degrees to 78+ degrees. I have a 1" durso overflow on the back upper corner of the display aquarium with a mag 7 return pump. Evaporative cooling is currently provided by 4 high CFM fans in the canopy controlled by an apex controller and two fans over the sump. My concern is that the addition of another mag 7 pump may negate any benefit that I may receive from my chiller.
Instead, I would like to try installing the chiller in line with 1 return pump that may operate at a cooler temperature. Has anyone had better luck with other brand return pumps e.g. Eheim, Sicce, Tunze, etc? I am very limited on space and may not be able to install the return pump externally. However, I am considering building a platform to raise the pump out of the water... Any information on your experiences or advice would be greatly appreciated. Thanks!