Underwater Treasures Floating Glass Fish Thermometer

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$1.75 Chewy Price
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About This Item

Details

  • Unique floating thermometer lets you monitor temperature fluctuations across your aquarium (sold separately).
  • Provides accurate and easy-to-read temperature measurements.
  • Use the strong suction cup to hold the thermometer in place between use.
  • Displays temperatures in both Celsius and Fahrenheit.
  • Smooth glass surface resists fogging and algae growth.

Frequently bought together

Questions & Answers

1 Customer Questions

Is the green area on the thermometer the area I want my tank temp at? Even with a magnifying glass I cannot read the numbers.

Answer by Chewy • Nov 07, 2025
The green area marks between 60-80F.
Reviews
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4.4
Rated 4.4 out of 5 stars
247 Ratings
Terms & Conditions

67 Customer Reviews

Rated 3 out of 5 stars
By D cat mom on Dec 13, 2025

Have used these in the past. Good price.

Pretty good item. Only problem is the suction cup quits working after a while, then it floats around and the bottom breaks if it hits something. But overall they

Pretty good item. Only problem is the suction cup quits working after a while, then it floats around and the bottom breaks if it hits something. But overall they last 6 months or so.

Rated 5 out of 5 stars
By Judith on Oct 2, 2025

The price and positive reviews

I’ve added a heater to my betta bowl, and needed a thermometer that wouldn’t take up a lot of space. This one definitely does the job. It’s a little hard to read

I’ve added a heater to my betta bowl, and needed a thermometer that wouldn’t take up a lot of space. This one definitely does the job. It’s a little hard to read but it’s ok. It adheres well to the bowl. I like that it’s glass for keeping it clean, etc. It also lets me monitor that the heater is working properly. So far, the two are a winning combination! Charmer is a happy camper.

Rated 2 out of 5 stars
By Tulin on Oct 18, 2025

Very difficult to read

I guess maybe this is why the thermometer is priced low. Not only are the ticks hard to see, but the red liquid in the pipe is very hard to see. Even with a magnifying

I guess maybe this is why the thermometer is priced low. Not only are the ticks hard to see, but the red liquid in the pipe is very hard to see. Even with a magnifying glass it is very hard to figure out the temperature reading.

Rated 5 out of 5 stars
By Steffani on Nov 16, 2025

Necessary

I wasn’t sure if my sticky one was accurate or not. This one is.

I wasn’t sure if my sticky one was accurate or not. This one is.

Rated 1 out of 5 stars
By Marvin on Aug 17, 2025

thermometer numbers way too small

The numbers on this thermometer were so small I had trouble reding them with my reading glasses & a magnifying glass. I threw this thermometer away.

The numbers on this thermometer were so small I had trouble reding them with my reading glasses & a magnifying glass. I threw this thermometer away.

Rated 5 out of 5 stars
By PM on Aug 27, 2025

Floating is cool

Always good to know what temperature the water is. Small enough to be out of the way and entertains the fish at feeding time.

Always good to know what temperature the water is. Small enough to be out of the way and entertains the fish at feeding time.

Rated 3 out of 5 stars
By Steven on Sep 28, 2025

Inconsistent quality

I have three of these in the tank currently, all three say something different.

I have three of these in the tank currently, all three say something different.

Rated 5 out of 5 stars
By Valerie on Sep 4, 2025

Good

I like to be sure my heater is doing its job so this is pefecg

I like to be sure my heater is doing its job so this is pefecg

Rated 5 out of 5 stars
By Carmen on Jun 6, 2025

Simple design and easy to read

I liked this design much better than the sticker thermometer. The red makes it mush easier to read . Good product for my new fish tank!

I liked this design much better than the sticker thermometer. The red makes it mush easier to read . Good product for my new fish tank!

Rated 5 out of 5 stars
By JD on Oct 28, 2025

great

works well and not too big or small

works well and not too big or small