Heater problem?

[SpikeAZ]

I have a 75g tank, 35 gallon sump, and a 300w Hagen heater in the sump.

I currently don't have my lights set up yet, the room is quite cool, and the tank is currently cycling.

My problem is that even though I have my heater set close to 90 (I want a constant 80 if possible), the temp of my new tank fluctuates between 76-78. The heater is never on for more than 30 sec. It has been like this for about 4 days (since putting the heater in there).

Do you think my heater is defective?

 

[pearsont74]

wow....i wish i had ur problem
i have to keep a fan running on mine to get it about 80

 

[greenmaji]

5wpg does the trick almost all of the time... looks like you need a 250watt added to to what you have and you should be set... HTH

It kicking off is probably a safety mechanism to keep from burning out the heater.. it is probably designed to tell if the water is heating up fast enough and if not it just kicks it off.. just a guess on this one..