Inconsistent Heating

[daisymoonbeam]

Ok, I really need some help with this. I just can't seem to ge the heat in my tank to stay consistent.

It seems that every five days (weirdly almost to the day) my heater decides to overheat. I am using a 100 Watt Stealth and am on the third one since all of them have done this. It is my understanding that for a 46 gallon tank I really should have two 100 Watt heaters but am afraid to add the other one because I can't seem to get even one to stay consistent.

For the past few days the temps have been a very level 78.7 to 79.7 at the hottest part of the day with the lights on. Today from 5:45 pm to 8:30 pm the temp went from 79.7 to 81.1. Nothing in the tank is different from all the other days, the temps outside and in the house are all pretty much the same. I keep the house at 72 or 73 all the time.

I am just as frustrated as I can be over this and have been battling this weekly re-occurance for at least a month.

Any help or suggestion would be soooooooooooo appreciated at this point.

Thanks

 

[daisymoonbeam]

By the way, the heater is set to 79.25 I think and has been for the last week, haven't touched it or anything else.

 

[Sk8r]

I gathered some good recommendations on a thread titled "heater on timer?" in the equipment forum. Apparently there are better heaters.

 

[bertoni]

I use Tronic heaters, mostly, since they seem to fail "off" rather than try to cook the tank. The breeders forum has other quotations along that line. I do use two of them, and a separate DIY "thermal shield" that is effectively a temperature controller. I don't know of any brand of heater that I'd trust (again). Too many animals lost to bad heaters.