Heater too hot

[Phoenixphire55]

So I never used heaters in the past because my apartment was fairly warm and the temperature stayed constant. However now that I live in Denver it gets very cold at night and in the morning. I found an old heater I had, not sure what kind it is or what size tank it was meant for but its about 7 inches long. When I put it in my ACF tank it made the water increase to about 82 degrees after only a day, so I removed it. Next I put it in my 20g long tropical tank and the water quickly shot up to 80 as well. I've taken it out and put it away, but can someone give me some info on using heaters? The one I used has a little stick coming out of the top which has an indicator to twist one way to increase the temp and the other to decrease it, but according to that its on its lowest setting and it still makes the water way too warm.

 

[Zagz]

Without know what wattage it is hard to tell you anything specific. Sometimes older heaters are unreliable. I would pick up a new heater and try that.

 

[rich311k]

It is probably shot. Go get new ones, save yourself the grief.

 

[Purrbox]

My guess is that the heater is stuck on and as a result no longer usable.

 

[2cvbloke]

You could clean it up and use it to keep a pot of coffee warm...

 

[Phoenixphire55]

I threw it away. I noticed water got inside it (yikes...). My little balloon molly died though, maybe because of the stress of the tank getting too warm. Poor little fishy. Oh well, she was the odd fish out. The other mollies are three sisters, their collective boyfriend (sailfin), and two new daughters. I've said this on like four other posts (lol) but the new girls are going to be really awesome looking once they get full sized. Beautiful colors. Very Halloweeny. Oh, I forgot for a second that I have two other mollies, but they are sisters as well.

 

[2cvbloke]

I threw it away. I noticed water got inside it (yikes...)

Yikes indeed!!! The heater we got with the big tank suffered this too before I even plugged it in, but my mum's partner decided to plug it in anyway (out of the water) and it popped the glass tube off!!!

 

[JohnPaul]

If you need a new heater, I highly recommend the Visitherm Stealth line. Aluminum insides, black plastic outside, completely submergable, very high quality. Many pet stores carry them, but you can buy them online from places like Dr. Foster Smith or AquariumGuys and pay probably half the cost of what you are going to pay in stores. (When I recently needed to get one for a 10 gal tank, the 50W was $29.95 at my local PetSmart but only $15.29 to buy it online.) Even with shipping, it's cheaper to buy one online and if you need to get more than one, or get other supplies at the same time, it's a truly great deal.

Visitherms at Dr. FS
Visitherms at AG

Note the "tank size" listed is the max tank size. So the 25W is good for tanks up to 8 gallons, the 50W for tanks up to 15 gallons, etc. This is presuming you are keeping your tanks in rooms that are reasonably heated. If the room with the tanks actually falls to temps below what most people would call "normal" room temperature, then I'd recommend going to the next size larger than the chart suggests. And once you get beyond a certain length of tank (55 gal and up, IMO, though others might have differing opinions), I think it works better to have two, lower wattage thermometers rather than one big one. This is especially true if water circulation is rather low.