Editor's Choice - Our Favorite TOPINCN Aquarium Hydrometers

1. 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 [star rating='4.2']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.4']

Here Are Some Other Related Aquarium Hydrometers

2. 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']

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. Pet Dog & Cat Refractometer,V-Resourcing Pet Urine Specific Gravity (1.000~1.060) Clinical Refractom...

User Ratings: 79

V·RESOURCING VLT065 First Impressions

"Seems pretty solid."

I found mine was calibrated out of the box. The water was at what I expected it should be. 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's a basic but reliable refractomer I use it for my aquariums. This refractometer came with two scales and Automatic Temperature Compensation. I got this to have a more accurate read than the hydrometer.

• Pet Dog & Cat Refractometer,V-Resourcing Pet Urine Specific Gravity (1.000~1.060) Clinical Refractometer with Serum or Plasma Protein Test (2~14 g/100ml) for Veterinary Cat,Dog, Pets
• 1.Hand-Held Pet Urine Specific Gravity Refractometer with Automatic Temperature Compensation(ATC: 10℃~30℃)
• 2.[ Measuring Range ] Dog Urine Specific Gravity:1.000~1.060 ; Cat Urine Specific Gravity:1.000~1.060 ; Serum or Plasma Protein:2~14 g/100ml
• 3.[ Easy to use ] Place 2 - 3 drops of sample onto the prism, and then look through the eyepiece for both Brix and Specific Gravity readings
• 4.[ Convenient to store ] Compact in size and light in weight, packed with a plastic case, convenient to store and carry around
• 5.[ Application ] This product provides quick and accurate indication of vital fluids levels.Ideal for clinical usage and intended for Veterinary
• N.W. of a piece: about 102g
• Product Size:19.5*4*4cm
• Package Weight:237g
• Manufacture: V-Resourcing

• Editor's Impressions Of The V·RESOURCING VLT065
• Accuracy [star rating='4.8']
• Quality [star rating='3.9']
• Value For Money [star rating='5']
• Affordability [star rating='4.5']

5. 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']

6. Tiaoyeer Salinity Refractometer with ATC Refractometer for Seawater, Pool, Tank, Testing, Marine, Fi...

User Ratings: 70

Tiaoyeer First Impressions

"Would buy another!"

This refractor should last a good number of years. I have a 2000+ gallon pond and I just put salt in it last month. I have a 2000+ gallon pond and I just put salt in it last month. Definitely a lot cheaper than a refractometer. Clear readout with the ability to calibrate and focus. I HIGHLY recommend this to Aquarists! It is easy to read and perform the procedure in seconds.

• Tiaoyeer Salinity Refractometer with ATC Refractometer for Seawater, Pool, Tank, Testing, Marine, Fishkeeping, Dual Scale-Specific Gravity 0-100PPT & 1.000-1.070
• ACCURATE READINGS : The Aquariums refractometer can measure on 2 Scales Aquariums refractometer features Specific Gravity (D 20/20) 1.000-1.070sg and parts per thousand 0-100PPT (1‰=1ppt=1000ppm)
• ADVANCED AUTOMATIC TEMPERATURE COMPENSATION（ATC）TECHNOLOGY：Adjust Automatically to Compensate for Temperature, Which makes it even easier to get fast results.
• SIMPLY USE: Using the dropper to take a sample of wort and put it on the prism. Then hold the refractometer up to the light and look scale through the eyepiece.
• WIDE USE: The Salinity Refractometer is ideal for Marine Monitoring, Aquariums Water Monitoring, Swimming Pool Water Measuring, Lab or Industrious Purposes.
• PORTABLE SALINITY CONTENT TESTER: Easy to use, sturdy design, compact in size and light in weight, convenient to keep up and carry around.
• ACCURATE READINGS : The Aquariums refractometer can measure on 2 Scales Aquariums refractometer features Specific Gravity (D 20/20) 1.000-1.070sg and parts per thousand 0-100PPT (1‰=1ppt=1000ppm)
• ADVANCED AUTOMATIC TEMPERATURE COMPENSATION（ATC）TECHNOLOGY：Adjust Automatically to Compensate for Temperature, Which makes it even easier to get fast results.
• SIMPLY USE: Using the dropper to take a sample of wort and put it on the prism. Then hold the refractometer up to the light and look scale through the eyepiece.
• Manufacture: hsydzsy329
• Product Dimensions: 5.7 x 1.37 x 1.37 inches; 8.78 Ounces

• Editor's Impressions Of The Tiaoyeer
• Accuracy [star rating='3.7']
• Quality [star rating='3.2']
• Value For Money [star rating='4.8']
• Affordability [star rating='5']

7. Seawater Salinity Refractometer,V-Resourcing Automatic Temperature Compensation Sea Water Salinity M...

User Ratings: 64 8

V·RESOURCING COMINHKPR127692 First Impressions

"Good product."

I have tried others before but this has given me accurate and stable results. All very easy and I feel as though I am getting an accurate salinity reading. I did NOT calibrate, but am getting accurate readings. YOU WILL NOT get an accurate reading if there are bubbles on the needle. I run brackish tanks and it works perfectly. 027, I'm so glad I bought this one and it came spot on. Definitely a lot cheaper than a refractometer.

• Seawater Salinity Refractometer,V-Resourcing Automatic Temperature Compensation Sea Water Salinity Measurer for Aquarium, Hydrometer, 0-100ppt & 1.000-1.070 Salinity Specific Gravity
• Automatic Temperature Compensation: 10℃~30℃
• Measuring range: salinity: 0-100 ‰, Specific Gravity : 1.000 to 1.070
• Minimum scale: salinity: 1 ‰, Specific Gravity : 0.001
• Resolution: salinity: ±1‰, Specific Gravity : 0.001 mm
• Perfect for salty water tank and aquarium, seafood water tank, salty pools & spas and etc
• 1*Salinity Refractometer
• 1*Mini-screwdriver
• 1*Pipette
• Manufacture: V-Resourcing
• Product Dimensions: 8 x 3 x 2 inches; 8 Ounces

• Editor's Impressions Of The V·RESOURCING COMINHKPR127692
• Accuracy [star rating='4.1']
• Quality [star rating='3.3']
• Value For Money [star rating='5']
• Affordability [star rating='5']

8. TRZ Salinity Refractometer for Aquariums, Marine Monitoring, Saltwater Testing, Dual Sacle 0-100ppt ...

User Ratings: 58 7

TRZ Hamh Optics&Tools First Impressions

"Using for my Pacman frog."

Plus it is super easy to use and clean. Very quick to calibrate and to use. I bought this refractometer as a more accurate option for salinity than a hydrometer. It works, we'll i assume it does as i have nothing to compare it to. I think those reviews just didn't know how to use it properly. Do not spend money on calibration fluid to calibrate this meter. I've tried several different refractometers now and they are mostly the same.

• TRZ Salinity Refractometer for Aquariums, Marine Monitoring, Saltwater Testing, Dual Sacle 0-100ppt Salinity & 1.000-1.070 Specific Gravity Automatic Temperature Compensation.
• It is more accurate than a hydrometer and easy to measure. Designed for the testing the concentration of salt water and brine, perfect for use with aquarium Marine monitoring and quality control in scientific research and clinical laboratories
• Measurement range: Salinity 0 - 100 ppt, (0 - 10% salt content), SG 1.000 to 1.070 SG, Resolution: Salinity +/-1 ppt; +/-0.001 SG
• Easy to use. Place 2 drops sample on the main Prism and close the panel and hold the refractometer up to the light and look through the eyepiece.
• The refractometer's body and the retaining ring are made of brass and chrome plated. The internal optical lens with high refractive index make up the precision optical system.
• Please ignore reviews from Diver. This commentator has a suspicion of being hired. Seller opponents use unfair means to compete！
• Manufacture: Hamh Optics&Tools
• Item Weight: 5.6 ounces
• Product Dimensions: 7.48 x 2.17 x 1.38 inches

• Editor's Impressions Of The TRZ Hamh Optics&Tools
• Accuracy [star rating='3.3']
• Quality [star rating='4.6']
• Value For Money [star rating='5']
• Affordability [star rating='4.1']

9. AUTOUTLET Salinity Refractometer for Aquarium Salinity Tester with ATC and Dual Scale 0-100‰ & 1.0...

User Ratings: 89

AUTOUTLET First Impressions

"Better than nothing."

027, I'm so glad I bought this one and it came spot on. Then I made a mark on it to set the salinity of my fish tank. Once I adjusted the refractometer, my aquarium salinity read 1. If you let it sit in the tank overnight, it definitely gives an accurate reading. It's a basic but reliable refractomer I use it for my aquariums. I think those reviews just didn't know how to use it properly. Used distilled water to calibrate, the screw is located under the rubber cap.

• AUTOUTLET Salinity Refractometer for Aquarium Salinity Tester with ATC and Dual Scale 0-100‰ & 1.000-1.070 Specific Gravity Saltwater Tester for Seawater Pool Fish Tank
• Dual scale display provides readings of one-thousandth (0-100PPT) and specific gravity (1.000 to 1.070 SG), and replace the hydrometer for easier and more accurate measurement.
• Automatic temperature compensation. With the help of the ATC function, the salt water tester can automatically compensate for changes in the ambient temperature, which can obtain accurate readings faster and more easily.
• Durable and portable, the salt water tester is made of non-staining, non-corrosive and non-reactive aluminum material, with superb technology, strong and durable, light weight and easy to carry.
• Widely used, can be used for aquarium, marine monitoring, agriculture, horticulture and educational purposes (biological projects).
• Easy to use, salinity refractometer is easy to operate, only 2 drops of sample after calibration can get accurate reading through eyepiece.
• 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

• Editor's Impressions Of The AUTOUTLET
• Accuracy [star rating='4']
• Quality [star rating='4.3']
• Value For Money [star rating='5']
• Affordability [star rating='5']

10. Hikari AccuProbe Aquarium Hydrometer, Mini

User Ratings: 55 45

Hikari 96005 First Impressions

"NO BUBBLES!"

However, the numbers are soooo small it is sometimes hard to read. Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. It's fast, it's tidy, and it's accurate. I did NOT calibrate, but am getting accurate readings. Definitely a lot cheaper than a refractometer. Ultimately, the measurement was exactly the same as our old tester. Calibrate with distilled water and test every so often.

• Hikari AccuProbe Aquarium Hydrometer, Mini
• Ideally suited for use in Nano tanks, smaller setups or sumps of larger systems
• Accurate to 0.001 specific gravity and salinity (PPT) measurements
• Durable construction for extended life
• Designed to give a temperature-corrected reading in warm water aquariums – 68°F to 85°F (20°C to 30°C)
• Readings can be taken by taking the meter out of the aquarium and placing on a level surface or leveling the unit in the substrate
• Manufacture: Phillips Feed & Pet Supply Natural Balance
• Product Dimensions: 5.2 x 1 x 3.5 inches; 0.8 Ounces

• Editor's Impressions Of The Hikari 96005
• Accuracy [star rating='3.9']
• Quality [star rating='3.8']
• Value For Money [star rating='2.2']
• Affordability [star rating='4']