Good point. I think my chiller (when I was using it), peaked at start up of 10 amps then fell off to 3-5 amps during operation.
Pumps can be a source of heat buildup in a tank. If your running one or more danner supreme mag drive pumps, they are heat factories. They (mag 9.5) build up so much heat that my 75 gal. mixing barrel gets to hot in the summer to do a water change immediatly. I have to wait till it cools off or run a couple smaller maxi jets to keep the water moving.