SG wrote in
able.rogers.com:

In article ,
Charles Flakus j.r. wrote:
My air conditioner broke today while I was at work.

turn off any lights
remove hood
aim fans at water surface

It does an amazing job at cooling tanks down.



I agree completely. I made the mistake of leaving the lights on in
similar conditions, and lost most of a tankful of Tanganyikans. The
immediate danger of high temperatures is that the ability of water to
retain dissolved oxygen decreases as the temperature increases.
Moreover, lights heat the surface of the water and the air just above it;
I believe this makes oxygen absorption even more problematic in such
circumstances. Fortunately, it sounds as though the original poster has
very low fish densities however. (He only mentioned one fish per tank).
I think this bodes well for his fish surviving the crisis. One
additional measure that might be taken is to increase water circulation
and make water changes.

Meph