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
  • Quality
  • Value For Money
  • Affordability

GXSTWU HY-2 Final Thoughts

"Seems pretty solid."

Hate the batteries, but once loaded, it seems to work fine. If you let it sit in the tank overnight, it definitely gives an accurate reading. Like that it comes with everything needed. Get precise salinity readings in moments. I have to recalibrate it ever use though which worries me sometimes. This one read perfect, and the others were completely inaccurate. Plus it is super easy to use and clean.

Overall Score
4.4


(265 Points)

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
  • Quality
  • Value For Money
  • Affordability

Eyourlife Final Thoughts

"And accurate."

I've checked about 5 times with the hydrometer and each time has been near perfect. Great tool if you have a salt-water fish tank or a decorative pond. But there are some ways to keep on getting accurate readings. Pretty darn accurate for the price. So worth it considering its great quality and great price. Does just as good of a job of any meter you would buy at the store! It is a little cheaper made but it works great for the cost!

Overall Score
4.4


(18 Points)

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
  • Quality
  • Value For Money
  • Affordability

Hongzer Final Thoughts

"So far so good."

It is a little cheaper made but it works great for the cost! Pretty darn accurate for the price. Ambient room light at night is not enough and makes what you're viewing dark. Normally that gives the more accurate reading. Now its easy to make sure I have the correct amount of salt in my aquariums. I was surprise that the product was really cheap compare to the other ones. This refractor should last a good number of years.

Overall Score
5.0


(2 Points)

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
  • Quality
  • Value For Money
  • Affordability

Bubble Magus Final Thoughts

"Easy to use."

Functions just as it is supposed to. Be sure to buy the calibration solution and test this before use! Ambient room light at night is not enough and makes what you're viewing dark. It is a little cheaper made but it works great for the cost! I decided to upgrade and it was easy to calibrate. I would recommend this product to anyone that has a marine aquarium. So worth it considering its great quality and great price.

Overall Score
5.0


(1 Points)

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
  • Quality
  • Value For Money
  • Affordability

Jadpes Final Thoughts

"Couldn't do without it."

YOU WILL NOT get an accurate reading if there are bubbles on the needle. It did not need adjusting to calibrate, though I tried to just to see how it worked. This is perfect to keep a check on the salt level in your tank. Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. My only criticism would be that it's a little too dark. It is essential to get some specialized aquarium calibration fluid for 1. I have purchased before will buy again!

Overall Score
3.0


(1 Points)

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
  • Quality
  • Value For Money
  • Affordability

CIZTADA Final Thoughts

"Accurate so far!"

Too that makes it appear too cheap. It says in the instructions to use distilled water. This is perfect to keep a check on the salt level in your tank. Normally that gives the more accurate reading. Once I adjusted the refractometer, my aquarium salinity read 1. Bought this one to check my old one, this one checked right on the dot at 1. Bought this one to check my old one, this one checked right on the dot at 1.

Overall Score
5.0


(1 Points)

7. 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
  • Quality
  • Value For Money
  • Affordability

CIZTADA Final Thoughts

"Accurate so far!"

Too that makes it appear too cheap. It says in the instructions to use distilled water. This is perfect to keep a check on the salt level in your tank. Normally that gives the more accurate reading. Once I adjusted the refractometer, my aquarium salinity read 1. Bought this one to check my old one, this one checked right on the dot at 1. Bought this one to check my old one, this one checked right on the dot at 1.

Overall Score
5.0


(1 Points)

8. capetsma Salinity Tester, Accurate Sea Hydrometer Aquarium Marine Salinity Meter for Fish Tank Pond ...

User Ratings: 56 11

capetsma First Impressions

"Great Product, Thanks!"

Be sure to adjust the focus by turning the eye focal when you first receive. There are conversion charts and tables online. I have gone two years in this hobby with a hydrometer. Get precise salinity readings in moments. It is a little cheaper made but it works great for the cost! Make your own by simply boiling some water and collecting the condensate. There are conversion charts and tables online.

  • capetsma Salinity Tester, Accurate Sea Hydrometer Aquarium Marine Salinity Meter for Fish Tank Pond Water Saltwater Freshwater Specific Gravity Test
  • Safe Material & Unique Design: Made of durable Acrylic, this Fish Tank Test Kit salinity Hydrometer is designed with an automatic level function.
  • Quickly, easily, and accurately measurement: With this hydrometer saltwater aquarium test kit, you can test your marine aquarium's salt level and specific gravity, and It is optimum to be put into below 6" deep water to avoid the error caused by the oil film on the water.
  • Higher Accuracy & safe zone indicated: Readings are temperature-corrected & accurate to +/- 0. 001. specific gravity units ranges from 1. 000 - 1. 030 with a safe zone of 1.020-1.023. The outside range of scale indicates salinity ppt, ranges from 0-40, safe zone is 27-31.
  • Easy to Read & Clean: The easy-to-read swing-arm pointer and extra wide stable base provide an accurate test result. After use, soak this saltwater meter in mild acid(vinegar) for 30 minutes, rinse with tap water and air dry. Do not disassemble.
  • Wide Usage:Fit for brackish and reef salt marine aquariums. Perfect for testing both salinity and specific gravity of your brackish and marine tank.Includes salinity and specific gravity scales.Suitable for fresh water and sea water.
  • Manufacture: Capetsma
  • Editor's Impressions Of The capetsma
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

capetsma Final Thoughts

"Easy to use."

Be sure to buy the calibration solution and test this before use! If you let it sit in the tank overnight, it definitely gives an accurate reading. Plenty of info on YouTube and the web if you don't know how. Works great,& comes in a storage box. Hate the batteries, but once loaded, it seems to work fine. Too that makes it appear too cheap. So worth it considering its great quality and great price.

Overall Score
4.0


(69 Points)

9. TOPINCN Square Saltwater Hydrometer Salt Water Salinity Meter Accurate Automatic Hydrometer Salt Wat...

TOPINCN First Impressions

"Super easy to use."

Then I made a mark on it to set the salinity of my fish tank. This device is a godsend and so much easier and cleaner to use. 027, I'm so glad I bought this one and it came spot on. I would recommend you to purchase this and skip the other ones. This refractor should last a good number of years. Find a good light source to make reading easier. Just rinse with warm water afterwards.

  • TOPINCN Square Saltwater Hydrometer Salt Water Salinity Meter Accurate Automatic Hydrometer Salt Water Salinity Meter for Fish Tank
  • Accurate, durable, and easy to read sea water hydrometer
  • This product is designed with an automatic level function, can automatically identify the level to avoid errors
  • Very accurate measurement readings, please rest assured to purchase
  • And each hydrometer has a laser engraved patent number
  • Fit for brackish and marine aquariums. Perfect for testing both salinity and specific gravity of your brackish and marine tanks.
  • Manufacture: TOPINCN
  • Product Dimensions: 5.51 x 3.54 x 0.79 inches; 3.17 Ounces
  • Editor's Impressions Of The TOPINCN
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

TOPINCN Final Thoughts

"Case is nice as well."

The refractor was off out off the box. It works OK but seems pretty flimsy and it's feel that way. I got this to have a more accurate read than the hydrometer. This device is a godsend and so much easier and cleaner to use. Bubbles can greatly affect the reading. Be sure to adjust the focus by turning the eye focal when you first receive. Ambient room light at night is not enough and makes what you're viewing dark.

Overall Score
5.0


(1 Points)

10. Rhino Clinical Pet (Dog & Cat) Refractometer HR305 (ATC), Urine Specific Test

RHINO TECHNOLOGY First Impressions

"Easy to use."

If you let it sit in the tank overnight, it definitely gives an accurate reading. It's perfectly accurate based on the known calibration fluid. Functions just as it is supposed to. Plenty of info on YouTube and the web if you don't know how. I don't want to deal with temperature correction or. I've tried several different refractometers now and they are mostly the same. YOU WILL NOT get an accurate reading if there are bubbles on the needle.

  • Rhino Clinical Pet (Dog & Cat) Refractometer HR305 (ATC), Urine Specific Test
  • The Rhino Pet refractometer HR305 can be used to read Specific Gravity of Dog Urine, Specific Gravity of Cat Urine,and Serum or Plasma Protein.
  • We provide 2 years quality warranty and customize services for the Pet refractometer.
  • The surface of the refractometer is sprayed with Teflon,It has the characteristics of wear resistance, corrosion resistance, anti-static and anti-adhesion.
  • The Rhino Pet hand-held Refractometer come with portable holster, water bottle, calibration mini-screwdriver, english instruction manual, cleaning cloth, plastic pipette and case.
  • Rhino Pet refractometer with Automatic Temperature Compensation ( 50°F~86°F / 10°C~30°C ).
  • Manufacture: RHINO TECHNOLOGY
  • Editor's Impressions Of The RHINO TECHNOLOGY
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

RHINO TECHNOLOGY Final Thoughts

"Other then that."

I tried it over and over and no bubbles! I don't know if that's a positive or negative but just different. 027, I'm so glad I bought this one and it came spot on. I got this to have a more accurate read than the hydrometer. Looks to provide very accurate readings. I will get one later but for now this will do, since im just starting. And it is much more accurate than my old salinity meter.

Overall Score
5.0


(8 Points)

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