TyGuy asked in PetsFish · 1 decade ago

Is it safe to leave heater on in aquarium?

I recently bought a "Top Fin" 10 gallon aquarium with filter and heater. My aquarium houses 2 gouramis and 2 guppies, so I know water temperature should be about 74-80 degrees. However, with the horrible thermometer that came with the aquarium I can not accurately gauge the temperature. Although, based on tough it always feels really hot.

My question is do I have to unplug the heater once it gets too hot and then plug it back in when it gets too cold etc, or does it have a thermostat and thus it is safe to leave on?


Just realized the reason that temperature is increasing may be because heater was not completely submersed. Perhaps thermostat unit is on top?

14 Answers

  • Anonymous
    1 decade ago
    Favourite answer

    Your heater has on the top a thermostat which you need to regulate when you reach the water temperature you need, in that way when the temperature drops it begin to heat until your previously set temperature, and when it gets that temperature it will turn off by itself, that's a thermostat. See the users manual that came with the heater.

    About your thermometer you're right, is horrible, but you can buy another one for $3.

    Hope this could help

    Source(s): I bought a "Top Fin" 20 gal kit, is the same, just bigger
  • Katie
    Lv 4
    1 decade ago

    Absolutely not. Varying the temps like that can lead to illness and death. Were you fortunate to get a heater with a temp dial on it/ They're usually pretty close to what they say, at least when they're new.

    I have noticed when the weather is cold, and I feel the water in the tank, it always feels very warm, but the thermometer says it's what it should be. (during the summer when it's hot, the water fees cooler to me).

    You can get a thermometer and be sure your water temp is right. They have little strips (about $1.78) that have a sticky back. You stick them on the outside of the tank and you'll always know the temp at a glance. There are cheap thermometers that have suction cups, around 2.00, less at walmart, you can put in the water and stick to the side of the tank. You can leave them there indefintely or just long enough to find out the temp.

    From there, temps go up in price. The highest I've seen were digital ones for in the $20. The cheap ones do fine for me.

    Anyway, you might need a different heater unless it has a temp dial and you can adjust the temperature, after determining the temp of the water. Some of the cheaper ones are set at one temperature, which is usually around 78 I believe and you can't adjust them. But no, don't keep unplugging unless you find it brings the temp to extreme highs that will kill the fish and you can't or don't have a dial to turn the temp down. Yo also can't let the water get too cold or that wil kill t hem, so you'd be monitoring the tank all the time to keep it in the range they need.

  • karol
    Lv 4
    4 years ago

    Aquarium Heater With Thermostat

  • 1 decade ago

    No, it should always remained plugged in. To get a lower temperature, there should be a dial on the end of the heater. I suggest you get a thermometer as soon as possible to get an accurate reading. Keep in mind that changing the water temperature by your heater's setting will not be immediate and will take some time to either warm up or cool down. The heater is meant to maintain a constant water temp. Plugging it in and out would be the wrong way to use it and also be quite a hassle. For a thermometer, it's quite possible that some are inaccurate, especially cheap ones. There are right and wrong places to put the thermometer and also heater. Trust me one this when I say reading directions does help.

    Source(s): I have a top fin heater and also have years of aquarium experience.
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  • 1 decade ago

    Heaters except for the 7.5 Hydor pad come with an internal thermostat to control temps. There should be a way to control that temperature via a dial on the top.

    That being said, I strongly urge you to invest in a tank thermometer that is NOT by Top FIn to be certain! Top Fin products are not of the best quality, and their heaters are notorious for overheating tanks to 90+ and killing fish.

    Source(s): Owner of 4 Bettas Member of Ultimatebettas.com (many users have complained about Top Fin heaters there) Fish/Pet store employee (even if I don't work with customers)
  • 1 decade ago

    The heater is probrably a cheapie. My best advice is go to the pet store and but a better heater and thermometer. temp fluctuations are very stressfull to fish. if you purchase a heater this is VERY important. You can try this with the heater you have. unplug the heater for 15 minutes while immeresed in the water- this allows the heater to have a more accurate reading of the aquarium temp. after 15 min plug in the heater and slowly adjust the heater 1 click per minute. if your heater still appears stuck- you most likely need a better quality heater.

  • niesen
    Lv 4
    4 years ago

    Goldfish are high-quality with temperatures round 60 F. you do not choose a heater. you do not choose gravel to apply a submersible heater, although. A submersible heater attaches to the area glass. Or are you contemplating those heater cables that bypass less than the gravel? they does no longer artwork with goldfish-- the goldfish ought to dig them up.

  • 1 decade ago

    typically heaters come with an internal thermostat that will tell it to turn or or off.

    EDIT: yeah, the thermometer should usually be kept horizontally towards the bottom of the tank

  • 1 decade ago

    maybe your heater is too strong. i mean your tank is only a 10 gal and most heaters are made for larger thanks. i have a 50 gal with one heater i leave on at all times.

    turning your heater on and off is a bad idea i think. i mean how would you like it if your room temperature changed that often?

    get a new thermostat and maybe a new heater

  • 1 decade ago

    of course the heater will turn it self off when it gets to hot and when to cold it turn back on.

    maybe turn the temp down a little to 78 degrees

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