Heater problem or ......??

[TXFish]

Hi All,

I've got a Rena-Cal 100 watt submersible heater on my 20 gall tank. It's set at 79 and up until recently has maintained that temp well. Lately, however, the tank temp doesn't seem to get above 76, though I have not readjusted the heater. It's gotten a bit colder down here so the room temp has been around 70-72. I'm guessing that's the problem but I was thinking the 100 watt would've been sufficient to maintain the temp in the tank at 79????

Do I need to get a new heater or just not worry about it as long as the temp is reasonably stable??

Any thoughts? Thanks!

 

[Fishyfanatic]

Is the tank larger than 20 gal? If so, you'll need a larger heater. The guide is 5 wpg.

 

[Zagz]

My temps on the heaters on my tanks don't reflect the actual tank temp. I use an external digital thermometer for accuracy. The numbers on the heaters mean nothing to me LOL.

 

[Tiffi]

I've got a Rena-Cal 100 watt submersible heater on my 20 gall tank.

It is only a 20gal!

When I calculate 20x5 I get to 100?! So that's exactly 5wpg. It depends, if you would need a new heater. If you want to be on the safe side get a new one. If you say your room tempereature will stay the same during the winter you might be fine. I would say the heater is broke though, if it can't heat the 20gal. Do you have any warranty left?

 

[Fishyfanatic]

I didn't see the 20 gal remark. Sorry Tiffi, geez.

 

[TXFish]

Actually, the temp of 76 is coming from the thermometer and not the heater.

I guess I'm wondering if it's asking too much of a 100 watt heater to warm a 20 gall tank up to 10 degrees above room temperature?? I do see the heater coming on more frequently, but I was thinking it would heat the tank better than this.

Tiffi, I'm not sure if it even has a warranty--it came from Petsmart........guess I could try taking it back, though.

 

[patagonia]

did you try adjusting the heater to a higher temp? i agree with Zagz.... the marks on the heater really dont mean much....like her i have a digital thermometer and my tank water reads 86.5F and the heater is set at 88 or so (im treating ich btw...thats why temp is high)...set the heater a little bit higher and see what happens...

 

[Fishyfanatic]

10 degrees is a bit much. You may need to bump up the wattage. I used to have a link to a site that said how big of a heater is needed for each degree above room temp. I'll look for it.

 

[Mazdaman]

I don't thinkl the tank is 72 or 76 or 79. The temp. on the heaters are never 100% accurate as the heater is design for some different sized aquariums. 76 on a 15gal will be different of a 20gal. (at least in my experience) Try getting a seperate therm. to read the temp and use the dial to adjust based on the readings of the therm. And yes room temp will effect the tank temp... ...safest bet is getting a seperate therm.

 

[TXFish]

I guess I should have clarified......I do have a separate thermometer in the tank--it's the type that sticks on the inside of the tank with a suction cup. That's what I'm getting the 76 reading from.

I guess I always thought the heater dial was accurate because the thermometer read exactly what the heater was set at, although I suppose that could've been purely coincidental because the room temp was warmer than it is now. Going into the cooler season, this could turn into an ongoing problem over the next several months. I've turned the heater dial up to "81", so I'll keep an eye on it. I'm just worried about stressing the fish with temp fluctuations.

 

[Fishyfanatic]

Move the temp slowly. If you change the temp by 2 degrees every day, you won't cause any problems.

 

[TXFish]

Thanks . Since I bumbed up the heater dial, the tank is holding steady at 77.

Just in case I end up getting a new heater, which ones do y'all recommend??

Any opinions on the AP Rena-Cal (the one I have)? Just curious what experiences others have had with it?

 

[Fishyfanatic]

The Visi-Therm Stealth is a great heater and will not break since it is not glass. It automatically shuts off when it is out of water. Won Bros makes a good heater also, the temp dial is out of the tank so its easier to change the temp. They can be harder to find and pricier.