LOL. I run a reverse lit fuge. Main tank lights are on 7:30am to 8:30pm (plus an extra half hour on each end for dawn/dusk actinics). The fuge light kicks on at 7:30pm to 8:30am. My 65w fuge light (the $9 LOA fixture) runs hotter than my 4x65w Coralife PC fixture. My temp goes up at night!
In the winter this saves on heating costs, but I pulled the second fan out of the garage to go in the cabinet yesterday; I just need to put it on the timer with the fuge light this weekend.
With the tank rebuild, I may ditch the lighted fuge and just have it be a cryptic zone, since I'll have seagrass and macro in the main tank. I'll have to see how the pH and O2 levels do overnight before I pull the plug completely.
Something that surprised me -- I have my 20g goby/shrimp breeder tank detached from the main system right now because I have the chiller on the back patio instead of inline on pump. Apparently, this separate goby tank has a cooling effect on the overall system. There's no significant surface agitation in the goby tank, so perhaps it is the long PVC run back to the sump that acts as a radiator?
If so, it makes for an interesting cooling idea -- have your overflow run through a few loops of PVC before dumping into the sump.
And no, I don't recommend this for a main tank! I might be worth experimenting with on a prop system or something to see if it works.