i'm getting ready to set up the 70W version in my office at work. based on what i know about the 150W 28 gal JBJ (our
LFS has had one running for a few weeks) which runs at 79*F unchilled, i'd guess it's going to run right around 80*F, give or take.
the filter section is open, so there is a bit of evaporative cooling, and the fixture is raised above the coverglass, so there's good air circulation.
