Any temp between 24-26c 75-79f is about right for most of them. Some will go higher as in the case of zebs >30c or 86f but you have to make sure that you increase the aeration to compensate for this.
I base the main temp on the fish some like it cool some like it hot
I once keep a whip sp that was not happy at over 23 c
Some Hypans like it to be over 28 c
Spawning is going to demand cooler water down to under 24 c for some species
each one has a different temepature need. My suggestion is to look at the profiles of each. My only tip would be , the higher the temp, the more additional oxygen is needed either with a difffuser or air stone. cheers jk :thumbup:
For electricity economy I preferred 26C/78.8°F but with winter on and me worried that parts of tanks may be a bit chilly (its winter in Australia) I increased them to to 27-28C/80.6°-82.4°F.
This seems to favor the Hypans and Panaques as my L066 and L397 and even the Peckoltia L278 have spawned.