I just bought a 1.5 gallon tank and a crowntail betta today, and I was wondering if I should get a heater for the tank. I'm afraid to get one since the tank is so small, but the temperature is only 76, and it probably wont get much higher than that. Thanks!
I have bettas in small acrylic totes and use PennPlax Cascade 25w heaters. They are preset to 76 deg. out of the box but are fully adjustable, which I have found useful. (I believe that the Hydor minis are only meant to heat the water to just above room temp, and have to be plugged in/unplugged to control the temp.)
The Hydror holds around 78-79 degrees. It's more effective in sub-4 gallon tanks. Little 'preset' heaters struggle in larger tanks. 4-7 gallons a 25w will do ok, at 10g may as well get a 'real' 50w heater.
I use a Marineland 10w submersible heater that is preset at 78 degrees. It cost me around $20.
I also have a hydor 7.5w mini heater, but there is no preset temperature so it keeps on heating until you unplug it. I use this to warm up my fresh tap water before putting it into my tank