Heater Question

[Betta Newbie22]

Okay i recently bought a Tetra Submersible Heater 50 watt for my ten gallon divided betta tank. Because I didn't have a lot of money and had already spent 160 dollars on the whole set up. Anyway I got the Heater Home submerged it in the water like the box said plugged it in and the light came on so i thought it was working. I came back 5 mins later and the light was off. I looked at my Thermomater and it said my tank was in the 70's but this heater was supposed to heat my tank between 76-80 degrees. I took the heater back and exchanged it for a new one and it did the same thing again. I have my Aquarium light on now and with that on my tank stays below 80. My question is.. is it normal for my heater to do this? And if not is there anything i can do to fix the problem? I don't have money to go out and get a new one. So is it okay to just use my light on my Aquarium to heat my tank? does anyone else do this and is it safe for my fish? Please Help.

[1fish2fish]

Unfortunately those preset tetra heaters are pretty crappy. For a smaller tank they work great but IME they won't heat anything much larger than 3 gallons.. and even then they never get much higher than 76-77*

As for using the light to heat the tank. The issue with that is when you turn the light off at night the temperature will drop... this fluctuation in temp can be bad for your betta.

My suggestion is to leave the heater in there so at least they'll be getting a little heat and work on saving for a new heater.

You also may want to consider changing out your light bulb. I'm assuming that if your light is heating your tank that much that it is an incandescent bulb. A better option would be to get a compact fluorescent bulb (the twirly kinds) they put off less heat which keeps the water temperature from fluctuating.


The fluctuation is not going to necessarily kill your fish or even cause them to get sick, it's just not an ideal situation.

[Betta Newbie22]

Without the Light or the heater my tank has stayed in the 70's with the temp like that would it be okay for my fish to be in the tank until i got the heater?

[1fish2fish]

Do you have an idea of the exact temperature? Is it in the low 70s? The mid 70s?

It's not ideal but for a short term thing its fine. My advice would be to cut back on the feedings a little bit because in the cooler water their metabolisms will not be as active so they'll need less food.

Edited to Add..

Do you know what the temperature of the room they're in is? Is it possible you could close the vents in that room or put them in a warmer room such as a closet as a short term thing. Those are other ways to try to keep the tank at a warmer temp until you can get a better heater.

[Betta Newbie22]

Well the Fan is usually on when we go to bed but during the day its shut off and its stays pretty warm in here.. At night its around the 70's I cant sleep if its too cold haha

[jman828]

Not sure if you know this, but the thing with alot of heaters is if the temperature needs to be boosted alot the heater will heat in increments so it will gradually rise (as not to stress the betta with sudden temp. changes) for example when i change my bettas water after all the aclimatation is done the old and new water is at about 68 which i then heat to 80 and my heater will heat a bit then break and heat a bit so it's gradual and doesn't overheat the tank. But mine is also one where you set the temp. yourself...if you have a preset one they usually work badly so if you do i reccomend you get a settable one.
Best of luck!

[1fish2fish]

Can you be a little more specific than "around the 70s"? That could mean 71F or it could mean 76F. There's a big difference in those temps.

[Betta Newbie22]

I Just said forget this and went out and bought a better heater. Now my temp is right where it should be.. My BF said ''those fish are more spoiled than i am'' Sadly I think he's right haha

[Comet1993]

I think I may have the same heater as you. My heater keeps the water at about seventy-eight to eighty. It took a little while for it to do that, though.. Maybe it heats it slowly. =]

[Thunderloon]

Are you reading using an internal floating/suction thermometer, a sinking thermometer or an external tape thermometer?

A glass tank will lose 3 to 5 degrees through the glass in airflow, a sinking thermometer will read lower than the rest of the tank, etc.

I usually have a tape-on and a floating/suction thermometer, that way I can keep the variance in mind when I look at the tape in passing.