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. Ade Advanced Optics aaosal Professional Automatic Temperature Compensation Sea Water Salinity Refrac...

User Ratings: 68

Ade Advanced Optics aaosal First Impressions

"What else can I say."

I've tried several different refractometers now and they are mostly the same. When I saw the price offered on this one, I decided to buy and I love it. The refractor was off out off the box. I would suggest purchasing the salt calibration solution. I don't want to deal with temperature correction or. The product itself is very good quality and the included instructions are very clear. Looks to provide very accurate readings.

• Ade Advanced Optics aaosal Professional Automatic Temperature Compensation Sea Water Salinity Refractometer for Aquarium, Hydrometer, 0-100 ppt and 1.000-1.070 Salinity S.G.
• Manufacture: Ade Advanced Optics

• Editor's Impressions Of The Ade Advanced Optics aaosal
• Accuracy [star rating='3.5']
• Quality [star rating='5']
• Value For Money [star rating='4.5']
• Affordability [star rating='3.6']

3. Instant Ocean SeaTest Hydrometer

User Ratings: 59 6

Instant Ocean TK-504 First Impressions

"Calibrate it, use it."

Make your own by simply boiling some water and collecting the condensate. This one here was much cheaper,& exactly the same as they sold in the store. My only criticism would be that it's a little too dark. Normally that gives the more accurate reading. Used distilled water to calibrate, the screw is located under the rubber cap. Once I adjusted the refractometer, my aquarium salinity read 1. Hate the batteries, but once loaded, it seems to work fine.

• Instant Ocean SeaTest Hydrometer
• Marine hydrometer: Tests salinity and specific gravity in marine aquariums to help maintain a healthy tank
• Accurate: Precise, full-range readings - accurate to +/- 0
• Ready to use: Simply dunk in aquarium to fill with water, then set on level surface to read
• Easy to read: Clearly marked to show results
• Extra-wide stabilizer base: Two-color scale with a safe zone for simple results
• Manufacture: Instant Ocean
• Item Weight: 0.8 ounces
• Product Dimensions: 6.3 x 4.2 x 1.3 inches

• Editor's Impressions Of The Instant Ocean TK-504
• Accuracy [star rating='3.8']
• Quality [star rating='3.3']
• Value For Money [star rating='3.4']
• Affordability [star rating='4.5']

4. 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']

5. 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']

6. Coralife Energy Savers ACLAF877 Deep Six Hydrometer

User Ratings: 67 7

Coralife 100108103 First Impressions

"024 and my refracto read."

I found mine was calibrated out of the box. At first, I was getting bubbles sticking to the rotating arrow. Wipe down glass surface to dry it and put it back on the shelf til next time. So once your instant ocean shows a measurement. Does just as good of a job of any meter you would buy at the store! I tried it over and over and no bubbles! Simple to use, but if there are any air bubbles the results will be way off.

• Coralife Energy Savers ACLAF877 Deep Six Hydrometer
• Included components: All Components included in Picture and Description
• Cora life is one of the markets leading manufacturers of premium aquarium products
• Cora life's Hydrometer takes a true water sample at six inch depth
• Easy to read and accurate, this specific gravity meter is designed to give temperature-corrected readings in warm water aquariums
• Coralife is one of the market’s leading manufacturers of premium aquarium products
• Coralife's Hydrometer takes a true water sample at six inch depth
• Specific Gravity and Salinity PPT Scales
• Optimal Specific Gravity / Salinity range indicator on scale
• Manufacture: Central Garden & Pet
• Product Dimensions: 6.69 x 0.79 x 4.72 inches; 3.2 Ounces

• Editor's Impressions Of The Coralife 100108103
• Accuracy [star rating='4.8']
• Quality [star rating='5']
• Value For Money [star rating='4.8']
• Affordability [star rating='4.4']

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. Dr. Marine Saltwater Marine Aquarium Salinity Portable Refractometer Meter ATC 0~10% reef

Aquarium Equip D-803 UP鹽度檢測器 First Impressions

"Great Product, Thanks!"

I bought this and a hydrometer because of the reviews saying its not accurate. Great product I used for beer making and my saltwater aquarium. Bought this one to check my old one, this one checked right on the dot at 1. I needed this product and it is a lot less expensive than the local aquarium store. Simple to use, but if there are any air bubbles the results will be way off. I have purchased before will buy again! Don't spend your money on calibration solution.

• Dr. Marine Saltwater Marine Aquarium Salinity Portable Refractometer Meter ATC 0~10% reef
• This latest salinity refractometer is designed for testing the concentration of salt water and brine and used for quality control in research and clinical laboratories and marine industry. Its scale provides a direct reading of the specific gravity and concentration (Parts per Thousand) of salt in water.
• Manufacture: UP AQUA

• Editor's Impressions Of The Aquarium Equip D-803 UP鹽度檢測器
• Accuracy [star rating='4.1']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.2']

10. Fluval Sea Hydrometer for Aquarium, Medium

User Ratings: 46 17

Fluval 14356 First Impressions

"Works perfectly."

Hate the batteries, but once loaded, it seems to work fine. Like that it comes with everything needed. There are conversion charts and tables online. Now its easy to make sure I have the correct amount of salt in my aquariums. The product itself is very good quality and the included instructions are very clear. The reading is big enough for you to read and it comes with the batteries. Small problem with bubbles on the needle but other than that no issues.

• Fluval Sea Hydrometer for Aquarium, Medium
• Helps measure specific gravity and salt level in marine aquariums
• Features large, easy to read markings
• Simple design-blends in easily
• Item Package Weight: 0.185
• Manufacture: Fluval
• Item Weight: 0.81 ounces
• Product Dimensions: 1 x 5.5 x 7.9 inches

• Editor's Impressions Of The Fluval 14356
• Accuracy [star rating='3.5']
• Quality [star rating='3']
• Value For Money [star rating='2.7']
• Affordability [star rating='3.1']