IMO it should work fine, a lot of growers use this style of pump outside of the reservoir. The fluid moving through it should cool it, but you will only know by trying it out. You could do a test before you build your system by putting the intake and output hoses into a 5 gal filled bucket. You'd have to prime the pump by pouring water down the intake hose. Then let it run for a day checking it periodically. I can't see it getting too hot though, its just a magnetic pump.