If the tanks are less then 1 gallon (if I can remember correctly, they are) then I strongly suggest getting a larger tank, at the very least 1 gallon (as long as your water changes are frequent enough), but ideally 2.5g.
For tanks between 1-2 gallons, here are some of your options (I starred the ones I prefer):
- Marineland 10w (suctions to side of tank) *
- Marina 10w (suctions to side of tank) *
- ZooMed Bettatherm 7.5w (flat under gravel)
- Hydor Mini Aquarium Heater 7.5w (flat under gravel)
Last edited by denaliwind; 03-13-2011 at 04:09 PM.