The one outside, on my Tilapia grow out set up, gets exposed to outside ambient temperatures, of close to 100 degrees during the heat of the summer, to start with, that pump I had to use a longer outlet hose that was fiber reinforced, and actually use automotive type screw hose clamps on the ends, as I actually burst a silicone hose, and blew the ends off barbed fittings… the one in the house, that powers my main tank group, draws air conditioned air at a much lower temperature, and is 3 feet away from my gang valve, yet the gang valve gets hot enough, that I’m starting to have problems with the vinyl air lines that go to the tanks , at the gang valve, that is still hot to the touch… starting to think about cooling fins, and a section of hard line, or increasing the length of the larger diameter output hose, to try to cool the gang valve a little…