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Pets Fish & Reptile Supplies

Best Aquarium Thermometers

Updated February 2023
Bottom line
Pros
Cons
Best of the Best
Zacro LCD Digital Aquarium Thermometer
Zacro
LCD Digital Aquarium Thermometer
Customer Favorite

An easy-to-read digital thermometer with an LCD screen that displays temperature.

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Customer Favorite
Bottom Line

An easy-to-read digital thermometer with an LCD screen that displays temperature.

Pros

Creates accurate readings within 0.1 degrees. Equipped with a long-lasting LR44 battery. Includes suction cups to attach the unit to the outside of a tank and a probe to submerge into the water.

Cons

Reports of the battery on/off button being faulty, so the battery runs constantly.

Best Bang for the Buck
Marina Stick On Aquarium Thermometer w/ Suction Cup, 25W
Marina
Stick On Aquarium Thermometer w/ Suction Cup, 25W
Easy Setup

This floating thermometer gives you an accurate reading the old-fashioned way with an easy-to-read indicator.

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Easy Setup
Bottom Line

This floating thermometer gives you an accurate reading the old-fashioned way with an easy-to-read indicator.

Pros

No electronics; it's weighted at the bottom and reads the temperature in real-time. Suction cups keep it floating in 1 place. It measures from 30-120 degrees, depending on the tank and needs.

Cons

It's fragile, so watch how you use it.

Capetsma Aquarium Thermometer
Capetsma
Aquarium Thermometer
Cordless Design

A digital touchscreen thermometer with functions to switch between Celsius and Fahrenheit.

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Cordless Design
Bottom Line

A digital touchscreen thermometer with functions to switch between Celsius and Fahrenheit.

Pros

Sticks on the outside of the aquarium glass to prevent water infiltration. Features buttons to set high- and low-temperature warnings. Easy to operate. Big number displays. Includes 2 batteries.

Cons

Not very accurate when used on acrylic aquariums.

Fluval Digital Aquarium Thermometer
Fluval
Digital Aquarium Thermometer
Simple Yet Solid

A fast-reading, 2-in-1 digital aquarium thermometer at an affordable price.

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Simple Yet Solid
Bottom Line

A fast-reading, 2-in-1 digital aquarium thermometer at an affordable price.

Pros

This model sits in your aquarium and displays the water temperature and the room temperature at all times. It works in salt and freshwater tanks. No setups, great for kids who own fish.

Cons

The displayed temperature has a large margin for error.

PULACO Stick On Aquarium Heater/Thermometer Combo
PULACO
Stick On Aquarium Heater/Thermometer Combo
2-in-1

This heater works on aquariums from 1 to 6 gallons without any complicated settings or setup.

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2-in-1
Bottom Line

This heater works on aquariums from 1 to 6 gallons without any complicated settings or setup.

Pros

It's an ideal heater for small tanks. You can place it vertically or horizontally, depending on your setup. Light indicators let you know the basic information.

Cons

Some had issues with tanks close to the maximum stated size.

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BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and all opinions about the products are our own. About BestReviews  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and all opinions about the products are our own. About BestReviews  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.About BestReviews 
HOW WE TESTED

We recommend these products based on an intensive research process that's designed to cut through the noise and find the top products in this space. Guided by experts, we spend hours looking into the factors that matter, to bring you these selections.

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First Reviewed
July 25, 2021
54
Models
considered
10
Hours
researched
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Our Top Picks
Zacro
Best of the Best
Zacro
LCD Digital Aquarium Thermometer
Bottom Line
An easy-to-read digital thermometer with an LCD screen that displays temperature.
Shop Now
Marina
Best Bang for the Buck
Marina
Stick On Aquarium Thermometer w/ Suction Cup, 25W
Bottom Line
This floating thermometer gives you an accurate reading the old-fashioned way with an easy-to-read indicator.
Shop Now
Capetsma
Top Pick
Capetsma
Aquarium Thermometer
Bottom Line
A digital touchscreen thermometer with functions to switch between Celsius and Fahrenheit.
Shop Now
Fluval
Top Pick
Fluval
Digital Aquarium Thermometer
Bottom Line
A fast-reading, 2-in-1 digital aquarium thermometer at an affordable price.
Shop Now
PULACO
Top Pick
PULACO
Stick On Aquarium Heater/Thermometer Combo
Bottom Line
This heater works on aquariums from 1 to 6 gallons without any complicated settings or setup.
Shop Now
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