i have a 60g planted tank and so instead of lights off, i've cycled to lights on at night and off during the day.
but also during the day: lid off, bubbler and fans.
i'm in the san fernando valley (l.a.) and it's 100's these days. the tank is in an enclosed patio that doesn't get direct light, but has no air conditioning- so i have no choice regarding a/c.
it's been +-82. so far so good.
i may get a (used) fluval canister filter and let that live in a bucket of ice water and see how that goes - IF it gets even hotter.