[nemosworld]

I keep my tank at 74-75 degrees
the thing most people forget to do is to add a heater to the top off system, that's another source of temp swings.
another thing to do is have 2 heaters for your display, that way if one fails the other will still be working, I would say 2x 200 or 300 watt heaters on large displays up to 220 gals.