My house is a split level. I'm on the lower level, which is built into a hill. This gives a measure of natural cooling. It feels cooler here than it does if you go a mile away. The upper portion of the house has one window air conditioner. There isn't any central air. The three ten gallon tanks are having the same problems. I've unplugged their heaters. I had (3) Aeneus Cories die in a very short span of time. I'm quite sure it was the heat.

I've restarted a "siesta" or nap period during the afternoon for all 4 tanks(soon to be 7). I used to do this to help control algae growth. Now, I'm doing it to hopefully cool the tanks down a little. The biggest jump in temperature seems to come between 6 pm and 7 pm. The temperature can go up 1 full degree in that hour. I've reset the timers to shut off for the night at 7 pm.(I'm in the process of creating a mini fishroom. It's a closet off of my bedroom which is actually the coolest point in the house. I think I'd better hurry.)
How does anybody here adapt to rising water temperatures with heat-sensitive species?