great pumps for sure. but if you are using a mag 3 pump for a return you may want to consider a ehiem pump for similar flow rates. the flow stars start off at hmm 1300 gph i believe.
Great pump, I have the Flow Star 1500 on my 140. It is teed off to run two returns and a reactor. The only drawback, is it does raise my temp up by 1 to 2 degress; nothing a cooling fan won't fix Just my 2cents