Water too warm. Inaccurate thermometer?

[jkegley]

Background: I just purchased this 5.5 gallon tank kit and began cycling today. I've used quick start, stress coat, and a bit of fish flakes. The filter, heater, and thermometer are installed, but only the filter is plugged in for now. I rinsed and added black sand, and the tank is filled completely. No decor and no livestock yet.
My issue: the thermometer that came with the kit is a little glass one with a suction cup. The kit manual has no information on it. I have it fully submerged on the side opposite of the filter and heater, near but not touching the sand. The tank has sat for at least 2 hours now, and the thermometer reads about 84 degrees F. The heater is not plugged in, and my household sits around 68-70 degrees F.
Does this sound wrong? Should I just invest in a digital thermometer? Maybe I don't have a good sense for temperatures. Can I test it with a thermometer that you use under your tongue to compare? Lol. I wanted to add my fish as soon as my parameters were good, but not if I don't know the temperature.
This is the heater I purchased, and I'm afraid that if I turn it on without an accurate, additional thermometer, I'll hurt my lil guy.
Any and all insight is appreciated.

 

[JAMMYLEYLO]

Background: I just purchased this 5.5 gallon tank kit and began cycling today. I've used quick start, stress coat, and a bit of fish flakes. The filter, heater, and thermometer are installed, but only the filter is plugged in for now. I rinsed and added black sand, and the tank is filled completely. No decor and no livestock yet.
My issue: the thermometer that came with the kit is a little glass one with a suction cup. The kit manual has no information on it. I have it fully submerged on the side opposite of the filter and heater, near but not touching the sand. The tank has sat for at least 2 hours now, and the thermometer reads about 84 degrees F. The heater is not plugged in, and my household sits around 68-70 degrees F.
Does this sound wrong? Should I just invest in a digital thermometer? Maybe I don't have a good sense for temperatures. Can I test it with a thermometer that you use under your tongue to compare? Lol. I wanted to add my fish as soon as my parameters were good, but not if I don't know the temperature.
This is the heater I purchased, and I'm afraid that if I turn it on without an accurate, additional thermometer, I'll hurt my lil guy.
Any and all insight is appreciated.

Hello, this just sounds like a dodgy thermometer, i would certainly reccomend purchasing a digital thermometer. These can be found for under $5/£5 on amazon. These give much more accurate readings and like you said, you should check your water temperature as well as parameters to make sure you have the best possible climate for your fish.
I hope this helps and you get your tank all sorted.

 

[Colin_T]

Give it 24 hours and check the temperature then.

If you used hot or warm water to fill the tank, it will be warmer than the room temperature.

If the thermometer is still reading unusually high tomorrow, take it back to the pet shop and swap it for another one. Look at all the thermometers on the shelf and get one that has the same temperature as all or most of the others. If there are thermometers with unusually high or low temperatures, do not get those ones.

Do not use the digital thermometers that sit on the outside of the tank. They are not as accurate and can be damaged if someone presses them.

Yes you can use a normal thermometer for checking your own temperature, to check the aquarium water.

 

[Metalhead88]

It doesn't sound right, but those glass thermometers are some of the most accurate ones.