Ok first off let me tell you I am not keeping a fish in this tank!
Now what I am keeping is snails. But I know even snails need warmth as well as the plant in it so I need to know how to heat it. It is a 1 gallon acrylic hexagon tank so what ever it is it can't be hot enough to melt it or boil the occupants.
I thought mabey a reptile mat but I've heard these can get quite warm and I've also looked into a 7.5 watt "betta bowl" heater. But neither of these can be controlled. I've also tried a simple desk lamp and so far can get the temp up to about 77-78 degrees but I have to shut it off at night, and then is when I need it most.
Any suggestions are welcome and appreciated! ^_^