Yes, but if it sticks on it will heat up a small tank very fast....what would happen if i used a 300w heater in a 20 gal or a ten gal? is the thermostat supposed to kick in and shut the heater off when it reaches the set temperature? thanks
:thm: the issue you may find with an oversized heater is a short cycle.I have run a 250 watt heater in a 10 gal tank for about a year (its a stealth)
http://www.aquariacentral.com/forums/showthread.php?t=149723
I also ran a 75 watt cheapie (Meier's brand) in a 2.5 gal QT tank.
my 37 gat tank, has a 250 watt heater.
Had no problems.
Just get the thermostat set right, and keep an eye on it till you are comfortable.
BTW if the thermostat gets stuck on any heater, in any tank, it will get too hot.
you should upgrade your tank so it is a more suitable size for the heater you have available. ;o)
BTW if the thermostat gets stuck on any heater, in any tank, it will get too hot.