Editor's Choice - Our Favorite Digital Aquarium Hydrometers

1. GXSTWU Reptile Hygrometer Thermometer LCD Display Digital Reptile Tank Hygrometer Thermometer with H...

User Ratings: 71 5

GXSTWU HY-2 First Impressions

"Couldn't be happier."

I compared the readings using this hygrometer and the calibrated refractometer. But with alittle persistance I am able to read it. Not sure how accurate it is, but it's a good reference point. There are conversion charts and tables online. I will get one later but for now this will do, since im just starting. So once your instant ocean shows a measurement. Find a good light source to make reading easier.

• GXSTWU Reptile Hygrometer Thermometer LCD Display Digital Reptile Tank Hygrometer Thermometer with Hook Temperature Humidity Meter Gauge for Reptile Tanks, Terrariums, Vivarium
• 100% Brand New and High-Quality Reptile Tank Thermometer Hygrometer: Precise supervision of the temperature and air humidity in terrariums, vivariums and reptile tanks.
• Stylish Design: Stylish looking digital vivarum thermometer with hook and loop for easy to install to any reptile tanks or terrariums. Comes with a battery so you can use the thermometer immediately.
• Fantastic Value: This accurate reptile thermometer and hygrometer allows you to monitor the temperature and humidity in the reptile tanks at all times to makesure your beloved reptiles are in perfect health.
• Fahrenheit Celsius Convertible: Temperature can be display in Fahrenheit or Celsius by press the C/F hole on the back of the item with a paper clip.
• Quality Guaranteed: Our carefully sourced range of thermometer hygrometers are manufactured to the highest of standards our customers expect. And provide 365 days warranty, in case of any quality problems, please feel free to contact us by email, we will give you a satisfactory solution.
• Manufacture: Cangda Electronics Co., Ltd.
• Product Dimensions: 2.09 x 0.67 x 1.3 inches; 0.92 Ounces
• Batteries: 1 LR44 batteries required. (included)

• Editor's Impressions Of The GXSTWU HY-2
• Accuracy [star rating='4.7']
• Quality [star rating='4.7']
• Value For Money [star rating='3.5']
• Affordability [star rating='4.8']

Peoples Choice - Other Highly Rated Digital Aquarium Hydrometers

2. Eyourlife Salinity Refractomer Aquarium Optical Optics Refractometer with Auto Temperature Compensat...

User Ratings: 64 8

Eyourlife First Impressions

"So easy to use."

Great tool if you have a salt-water fish tank or a decorative pond. Ultimately, the measurement was exactly the same as our old tester. I have purchased before will buy again! Great product I used for beer making and my saltwater aquarium. I would suggest purchasing the salt calibration solution. I tried it over and over and no bubbles! Very quick to calibrate and to use.

• Eyourlife Salinity Refractomer Aquarium Optical Optics Refractometer with Auto Temperature Compensation ATC Digital Dual Scale Salinity Meter Hydrometer Specific Gravity for Saltwater Seawater Marine
• SALINITY REFRACTOMETER for measuring the salinity of salt water quickly and accurately, ideal for agriculture, industry and research application, such as Mariculture, Fish Culture, Aquarium, Marine Survey, Water Quality Monitoring, Salt Production, Manufacture of Normal Saline, Salinity Measurement in Food Processing etc. It can also be used for medical institutions and university research.
• DUAL SCALES: The Refractometer is a equipment to measure the liquid concentration(the concentration of salt) by using the light, working basis on that the liquid with different concentrations have different light refractive index. The Measures on 2 scales: Specific Gravity (0.001, Range: 1.000 - 1.070, D 20/20,) and Parts Per Thousand (1‰, Range: 0-100‰).
• ATC FUNCTION: Automatic Temperature Compensation during 10-30℃, eliminating data errors caused by temperature changes and guaranteeing a consistent accurate result.
• WITH DURABLE STORAGE CASING: With a sturdy and light weighted case, it is very convenient to storage and carry. The body is made of stainless steel and is very durable, the eyepiece is in high quality for better viewing, adopting optical glass lens rather than plastic lens for accurate measurement.
• PACKAGING: 1 x Salinity Refractometer, 1 Pipette, 1 x Instruction manual, 1 x Mini screwdriver, with a durable storage case.
• 1 x Salinity Refractometer
• 1 x Pipette
• 1 x Instruction Manual
• Manufacture: Eyourlife
• Product Dimensions: 7.91 x 2.99 x 2.2 inches; 5.6 Ounces

• Editor's Impressions Of The Eyourlife
• Accuracy [star rating='3.9']
• Quality [star rating='3.4']
• Value For Money [star rating='4.9']
• Affordability [star rating='5']

3. Aquarium Refractometer, Seawater Salinity Meter Aquarium Optics Refractometer Temperature ATC Digita...

Hongzer First Impressions

"Easy to use."

Functions just as it is supposed to. It is essential to get some specialized aquarium calibration fluid for 1. It is easy to read and perform the procedure in seconds. It did not need adjusting to calibrate, though I tried to just to see how it worked. Once I figured that out, it works great. Be sure to buy the calibration solution and test this before use! So once your instant ocean shows a measurement.

• Aquarium Refractometer, Seawater Salinity Meter Aquarium Optics Refractometer Temperature ATC Digital 0-10%
• 0 to 10% salinity, 0.01% scale.
• Durable aluminum body, durable and can use for a long time.
• Adjust the focus by twisting the handle.
• Compact design with rubber handle.
• Soft and flexible eyepiece for added comfort. Instant and reliable aqueous solution measurement.
• Manufacture: Hongzer
• Item Weight: 8.4 ounces
• Product Dimensions: 6.69 x 1.57 x 1.57 inches

• Editor's Impressions Of The Hongzer
• Accuracy [star rating='5']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='5']

4. Bubble Magus Digital Color Screen Salinity Meter

Bubble Magus First Impressions

"Good value."

YOU WILL NOT get an accurate reading if there are bubbles on the needle. Every time I leave to do something I come back and it's at the bottom of my tank. On the shaft of the refractometer, there's a little, rubber-covered nub. However, the numbers are soooo small it is sometimes hard to read. Just rinse with warm water afterwards. I use this for my 10g brackish and it works ok. Bought this as a back up refractometer.

• Bubble Magus Digital Color Screen Salinity Meter
• Manufacture: Bubble Magus

• Editor's Impressions Of The Bubble Magus
• Accuracy [star rating='4.8']
• Quality [star rating='5']
• Value For Money [star rating='4.1']
• Affordability [star rating='4.7']

Honorable Mentions - More Top Selling Digital Aquarium Hydrometers

5. Digital Salinity Meter, SA287 Portable Digital Salinity Meter High Precision Salinity Temperature Pe...

Jadpes First Impressions

"Works great for reefing!"

At first, I was getting bubbles sticking to the rotating arrow. Perfrct for someone learning or anyone for that matter. Works great,& comes in a storage box. Then I made a mark on it to set the salinity of my fish tank. Bubbles can greatly affect the reading. I tried it over and over and no bubbles! I think those reviews just didn't know how to use it properly.

• Digital Salinity Meter, SA287 Portable Digital Salinity Meter High Precision Salinity Temperature Pen Type Tester for Saltwater, Swimming Pool, Aquaculture, Aquarium
• WATERPROOF SALINITY METER:It displays the salinity value precisely, compact size and light weight, easy and portable to carry, convenient to use.This instrument can not only detect the salt content of edible salt, salt water pool and koi fish pond, but also the salinity of seawater, marine, salt water fish tank salt level testing.
• SALINITY TESTER:Digital Salinity Tester for Salt Water.The pen type salinity meter is a precision instrument for testing the salinity value of a solution.Quick and reliable manner for most regular water solutions' testing.
• WIDE APPLICATIONS:Suitable for saltwater, swimming pool, aquaculture, aquarium (seawater) and pond, food processing and health care products industry. Saltwater Tester for Seawater, Aquariums, Marine Monitoring.
• BACKLIT DESIGN:It adopts large screen LCD, PPT standard unit display, power display, power data protection function, automatic temperature compensation, dustproof and waterproof functions.
• APPLICATION:Its full-featured performance, easy operation and replaceable electrodes make it the best choice for rapid, accurate salinity testing in laboratories, sites and schools.
• Manufacture: Jadpes
• Product Dimensions: 0.39 x 0.39 x 0.39 inches; 5.29 Ounces

• Editor's Impressions Of The Jadpes
• Accuracy [star rating='3.3']
• Quality [star rating='2.9']
• Value For Money [star rating='3']
• Affordability [star rating='2.7']

6. Digital Salinity Tester for Salt Water - Aquarium Salinity Meter with ATC, IP67 Waterproof, 0-200 PP...

CIZTADA First Impressions

"Works great for reefing!"

Functions just as it is supposed to. Looks to provide very accurate readings. Waterproof if you accidentally drop it in the pool. Does just as good of a job of any meter you would buy at the store! I have a 2000+ gallon pond and I just put salt in it last month. Comes with a nice carrying case for easy and secure transportation. Good quality and simple to use refractometer.

• Digital Salinity Tester for Salt Water - Aquarium Salinity Meter with ATC, IP67 Waterproof, 0-200 PPT Large Range Multi-Parameter Tester for Seawater, Fish Tank, Hydroponics
• [Large Salinity Range] Ciztada salinity tester has 2 measurement modes, scale range: 0~9999 ppm/10.0~200 ppt and 0.00-25.00%, which is 2 times than the salinity refractometer
• [Automatic Temperature Compensation] Ciztada salinity tester is equipped with ATC part inside, during normal temperature, once calibrated, the temperature change would never affect the accurate of your measuring result. This makes it more convenient to use in different temperature
• [Easy Reading with LCD Backlight] There is no need to worry about seeing the displayed value if the light is insufficient. Ciztada salinity meter features a green backlit LCD to help you see the measurement results clearly in any situation
• [Multifunctional Salinity tester]: The Ciztada multi-parameter Tester can test Salinity, TDS, EC and Temperature in an accurate, quick and reliable manner for most regular water solutions' testing. Support One-tap switch from salinity to TDS/EC
• [Wide Applications]: Measures saltwater or salinity of water, ideal for aquarium, marine monitoring, salty pools & spas, koi fish pond, hydroponics and etc
• Manufacture: CIZTADA
• Batteries: 3 LR44 batteries required. (included)

• Editor's Impressions Of The CIZTADA
• Accuracy [star rating='5']
• Quality [star rating='4.6']
• Value For Money [star rating='4.6']
• Affordability [star rating='5']

Here Are Some Other Related Aquarium Hydrometers

7. Aquarium Equip UP Glass Saltwater Hydrometer - Reef Soft Coral Salinity Marine Fish Shrimp sea

User Ratings: 55 17

Aquarium Equip D667 UP??????? First Impressions

"No assembly required."

Hate the batteries, but once loaded, it seems to work fine. And it is much more accurate than my old salinity meter. Be sure to buy the calibration solution and test this before use! My only criticism would be that it's a little too dark. It is a little cheaper made but it works great for the cost! It works, we'll i assume it does as i have nothing to compare it to. I was surprise that the product was really cheap compare to the other ones.

• Aquarium Equip UP Glass Saltwater Hydrometer - Reef Soft Coral Salinity Marine Fish Shrimp sea
• 1. Easy to use 2. Green indicators are ideal range of water temperature and specific gravity for most salt water / marine aquariums 3. Hydrometer measures specific gravity 4. Need it for raising brine shrimp
• Manufacture: D667 UP玻璃海水比重計
• Product Dimensions: 0.8 x 0.8 x 6.2 inches; 0.3 Ounces

• Editor's Impressions Of The Aquarium Equip D667 UP???????
• Accuracy [star rating='3.6']
• Quality [star rating='3.6']
• Value For Money [star rating='4']
• Affordability [star rating='4.1']

8. AUTOUTLET Refractometer Saltwater Aquarium for Seawater,Pool,Tank,Testing,Marine Fishkeeping, 0-100P...

User Ratings: 83 2

AUTOUTLET 8541957195 First Impressions

"These seem spot on."

Not sure how accurate it is, but it's a good reference point. Ambient room light at night is not enough and makes what you're viewing dark. If you read the directions in the box for the refractometer it's for freshwater. And it is much more accurate than my old salinity meter. Waterproof if you accidentally drop it in the pool. My corals will be much happier now. It is a little cheaper made but it works great for the cost!

• AUTOUTLET Refractometer Saltwater Aquarium for Seawater,Pool,Tank,Testing,Marine Fishkeeping, 0-100PPT & 1.000-1.070 Salinity Tester with ATC Function Hydrometer Specific Gravity Salinity Meter Kit
• 【Salinity Refractometer】Measure Salt Water or Salinity of Water,Monitor and Control the Concentration of Salt Water and Brine,Ideal for Aquariums and Marine Applications.
• 【Measures on 2 Scales】Specific Gravity (D 20/20) and parts per thousand and replaces your poor quality and difficult to read hydrometer.
• 【Density Measurement Range】1.0-1.070, Minimum Scale is 0.001.
• 【Concentration Measurement Range】0-100‰, Minimum Scale is 1‰.
• 【ATC】Automatic Temperature Compensation, 0-10°C.
• Due to the difference of human focal lengths,when during adjusting, you may just need to rotate in reverse or re-adjust the distance between your eye and the eyepiece.
• It's necessary to keep the surrounding environment with sufficient brightness and suitable temperature during use. Generally,there is no error in the temperature between 10℃-30℃.(50℉-86℉)
• Specific Gravity (D 20/20) and parts per thousand and replaces your poor quality and difficult to read hydrometer.
• Manufacture: AUTOUTLET
• Product Dimensions: 7.87 x 3.54 x 2.36 inches; 8.48 Ounces

• Editor's Impressions Of The AUTOUTLET 8541957195
• Accuracy [star rating='5']
• Quality [star rating='4.2']
• Value For Money [star rating='4.9']
• Affordability [star rating='5']

9. Coralife BioCube Mini Aquarium Hydrometer

User Ratings: 37 28

Coralife 100115642 First Impressions

"NO BUBBLES!"

My corals will be much happier now. Every time I leave to do something I come back and it's at the bottom of my tank. And it is much more accurate than my old salinity meter. This device is a godsend and so much easier and cleaner to use. It is a little cheaper made but it works great for the cost! Just give me one simple, accurate reading to go by, and I'm happy. When I saw the price offered on this one, I decided to buy and I love it.

• Coralife BioCube Mini Aquarium Hydrometer
• Can remain submerged inside your aquarium or sump
• Know your salinity in a glance
• Compact design allows for discreet placement in the aquarium
• Ideal for all saltwater aquariums and sumps
• Manufacture: Central Garden & Pet
• Product Dimensions: 3.9 x 1 x 6 inches; 0.8 Ounces

• Editor's Impressions Of The Coralife 100115642
• Accuracy [star rating='3.4']
• Quality [star rating='4.3']
• Value For Money [star rating='2.8']
• Affordability [star rating='3.9']

10. Aquarium Salinity Refractometer for Brackish/Marine/Reef Tank Testing,Hobein Dual Scale Automatic Te...

User Ratings: 68 6

Hobein First Impressions

"Calibrate it, use it."

And always make sure there is no bubbles on the measuring unit. When I compared it to what my local pet store was reading my water at it was dead on. Be sure to adjust the focus by turning the eye focal when you first receive. Plus it is super easy to use and clean. Be sure to adjust the focus by turning the eye focal when you first receive. Was calibrated and worked perfect right out of the box. It is easy to read and perform the procedure in seconds.

• Aquarium Salinity Refractometer for Brackish/Marine/Reef Tank Testing,Hobein Dual Scale Automatic Temperature Compensation 0-100ppt & 1.000-1.070 Specific Gravity with ATC
• ❤DUAL SCALE: Measuring Ranges: 0-100 ppt of Salinity and 1.000 to 1.070 Specific Gravity (0-10%)the reading resolution is 0.1 %. Salinity Accuracy: +/-0.1%
• ❤APPLICATIONS: Aquariums, Marine Monitoring, Agricultural, Gardening & Educational Purposes (Biology Projects)
• ❤EASY TO USE:Automatic Temperature Compensation (ATC),Just need 2-3 drops of solution,you will be able to read accurately the result
• ❤PORTABLE AND DURABLE: Made with non-staining, non-corrosive and non-reactive aluminum material, light-weighted and portable, safe and durable
• ❤PACKAGE INCLUDES: 1 Refractometer, 1 Carrying Case, 1 Calibrating Screw Driver, 2 Pippets, 1 Cleaning Clothe, 1 Instruction Manual
• Manufacture: Hobein

• Editor's Impressions Of The Hobein
• Accuracy [star rating='5']
• Quality [star rating='4.9']
• Value For Money [star rating='3.9']
• Affordability [star rating='4.7']