I also keep my tanks in the garage. I’ve lost a lot of fish over 3 different summers. After the second summer of losses, the next summer I ended up dropping the water level to let the filter output give more aeration, added an air stone, and that seemed to work that 3rd summer. However, this past summer, I lost 2 fish due to the heat, but one of them was a cold water fish, but the other one...even though it was a tropical catfish, it didn’t make it. The Bichirs that it shares the tank with are all still alive.
It sounds as if your garage is underground and almost like a basement,such spaces are always much cooler than above ground areas,in my experience.I've never lost a fish here due to heat. It was 48c (119f) for a couple of days and didn't lose anything. The garage is double brick and "under" the house. God Bichirs here are like $400 USD for a 2-3" fish. Take good care of them lol
It sounds as if your garage is underground and almost like a basement,such spaces are always much cooler than above ground areas,in my experience.
Ah...that would probably help you quite a bit.It doesn't get quite that hot here during the summer but we do have triple digit dog day stretches and in my old house the basement is always comfortable.It is one of a few reasons why my tanks are down there.Nope, part of the house is built on top of it but it's at ground level. For some silly reason, people don't build basements in Australia.
Ah...that would probably help you quite a bit.It doesn't get quite that hot here during the summer but we do have triple digit dog day stretches and in my old house the basement is always comfortable.It is one of a few reasons why my tanks are down there.