How big a tank?
Run a fan over the water surface. Use the ice.
Slow is the way to go though.
Add an air stone with air pump. Get the water moving with bubbles. More surface area to cool. More gas exchange better for fish.
Now you know why I run 2 heaters at half the wattage each.
Quote me as saying I was misquoted.
Once you get rid of integrity the rest is a piece of cake.
The problem is you don't know what you don't know.
Here's to our wives and sweethearts - may they never meet.
If you agreed with me we'd both be right.