My tanks are way too cold!

I have a Hydor Theo 25watt in my 2.5 gal fry tank, and haven't had any problems. I like that heater because it has a temperature control dial, not a preset temp that you can't adjust.
 
if you go to a pet store that sells reptiles, you could probably find a heating pad that would work for that size tank. you just put the tank on top.
 
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