Editor's Choice - Our Favorite Gain Express Aquarium Hydrometers

1. Pen Type Salinity & Temperature Meter ATC NaCl Salt Water Quality Tester for Saltwater Aquarium Hydr...

User Ratings: 49 17

Gain Express 837-2 First Impressions

"Easy to calibrate."

Just rinse with warm water afterwards. I run brackish tanks and it works perfectly. Hate the batteries, but once loaded, it seems to work fine. I tried it over and over and no bubbles! Excellent piece of equipment for the price. The water was at what I expected it should be. 026 and the tank isn't, new animals will go into shock.

• Pen Type Salinity & Temperature Meter ATC NaCl Salt Water Quality Tester for Saltwater Aquarium Hydroponics Food
• MEASURING RANGE: 0~9999 ppm or 10.0ppt~100.0ppt or 0.0%~10.0% or 0.950~1.080 (S.G.) based on NaCl with ±%F.S ±1 digit / ±0.5°C Accuracy
• DISPLAY: Dual Temperature and Salinity in four measurement units (ppm, ppt, %, S.G) / 30 x 18mm LCD Size
• APPLICATION: Salinity measurement in fish pond, tank, aquariums, laboratories, food processing, hydroponics, Aquaculture, and other water monitoring facilities.
• FEATURES: Waterproof IP65 / One touch calibration / Auto power off and Non-Sleep mode disable / Multi points calibration
• POWER SUPPLY / SENSOR : 4 x LR44 button batteries
• User friendly easy to operate with One-touch calibration
• Manufacture: Gain Express Holdings Ltd
• Batteries: 4 LR44 batteries required.

• Editor's Impressions Of The Gain Express 837-2
• Accuracy [star rating='3.2']
• Quality [star rating='4.1']
• Value For Money [star rating='3.2']
• Affordability [star rating='3.8']

Peoples Choice - Other Highly Rated Gain Express Aquarium Hydrometers

2. Dual Scale Salinity Refractometer ATC 0-100ppt (0-10%) & 1.000-1.070 Specific Gravity, Portable Mete...

User Ratings: 76 4

Gain Express RES-10ATC First Impressions

"Documentation is limited."

So once your instant ocean shows a measurement. And always make sure there is no bubbles on the measuring unit. Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. But with alittle persistance I am able to read it. Make your own by simply boiling some water and collecting the condensate. Works great,& comes in a storage box. Trying to turn it by hand won't work.

• Dual Scale Salinity Refractometer ATC 0-100ppt (0-10%) & 1.000-1.070 Specific Gravity, Portable Meter Tester for Seawater Salt Sea Water Aquarium Brackish Reef Tank Marine
• Range: 0-100ppt (0-10% Salinity) and Density/ Specific Gravity 1.000-1.070 1ppt Salinity and 0.001 g/cm3 Density Resolutions
• Water or a salt (brine) refractometer preferred by aquarist, it checks saltwater & brine or salinity of water, best for aquariums and marine monitoring
• True seawater or a salt (brine) refractometer preferred by aquarist
• Calibrate simply by distilled water, comes with free screwdriver for calibration
• Has automatic temperature compensation (ATC) and has built with the highest and finest quality of aluminum & rubbe
• Manufacture: Gain Express Holdings Ltd
• Part Number: REB-32ATC
• Material: ABS Material for Handle
• Item Weight: 9.9 ounces
• Color: 0-10% Salinity
• Batteries Included?: No
• Batteries Required?: No

• Editor's Impressions Of The Gain Express RES-10ATC
• Accuracy [star rating='3.6']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.4']

3. Clinical Refractometer with ATC, Tri-Scale Serum Plasma Protein Test 2-14g/dl Urine Specific Gravity...

Gain Express REC-300ATC First Impressions

"Matches my hydrometer."

YOU WILL NOT get an accurate reading if there are bubbles on the needle. If you let it sit in the tank overnight, it definitely gives an accurate reading. Even the smallest bubble will throw the measurements way, way off. It is easy to read and perform the procedure in seconds. Pretty darn accurate for the price. Easy to use, easy to clean, easy to read. Definitely a lot cheaper than a refractometer.

• Clinical Refractometer with ATC, Tri-Scale Serum Plasma Protein Test 2-14g/dl Urine Specific Gravity 1.000-1.060SG, for Veterinary Vet Cat Dog Pets
• Animal clinical refractometer Tri Scale for Dog Cat Test of Serum protein and Urine specific gravity
• TRIPLE SCALE: Dog Scale Urine Specific Gravity is for Large Animal, Cat Scale Urine Specific Gravity is for Small Animal and Serum or Plasma Protein Scale for all animals
• MEASURING RANGE: Dog and Cat Urine specific gravity: 1.000 - 1.060SG ; Serum Protein: 2-14g/dl
• Cushioned w/ soft and comfortable non-slip rubberized grip, insulate test solution from body heat
• Auto Temperature Compensation (ATC), rest easy that your measurements are always accurate regardless of temperature variation
• Manufacture: Gain Express Holdings Ltd
• Part Number: REC-300ATC
• Item Weight: 9.2 ounces
• Color: Urine Sg / Serum Protein
• Batteries Included?: No
• Batteries Required?: No

• Editor's Impressions Of The Gain Express REC-300ATC
• Accuracy [star rating='4.2']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.2']

Here Are Some Other Related Aquarium Hydrometers

4. Aeroway Salinity Refractometer, Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.)

User Ratings: 79 3

Aeroway 8541957182 First Impressions

"021 the other read."

Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. Normally that gives the more accurate reading. I will get one later but for now this will do, since im just starting. I run brackish tanks and it works perfectly. I strongly recommend a refractometer vs. This device is a godsend and so much easier and cleaner to use. On the shaft of the refractometer, there's a little, rubber-covered nub.

• Aeroway Salinity Refractometer, Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.)
• Measure salt water or salinity of water, ideal for aquariums and marine monitoring.
• Features automatic temperature compensation (ATC),The main part is made of chromium, it's very durable.
• Measures on 2 scales, Specific Gravity (D 20/20) and parts per thousand (‰).
• Comes with hard case, dropper, screwdriver and cleaning cloth.
• We offer premium quality and the best service, no matter what reason cause dissatisfaction,just return it within 30 days for a full refund. No questions asked, no hassle.
• Manufacture: Aeroway

• Editor's Impressions Of The Aeroway 8541957182
• Accuracy [star rating='3.7']
• Quality [star rating='4.2']
• Value For Money [star rating='4.9']
• Affordability [star rating='4.7']

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

8. 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']

9. Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Tempera...

User Ratings: 80 3

Agriculture Solutions WL0020-ATC First Impressions

"Would buy another!"

Very quick to calibrate and to use. I strongly recommend a refractometer vs. This is perfect to keep a check on the salt level in your tank. This device is a godsend and so much easier and cleaner to use. There are conversion charts and tables online. This requires repeatedly tapping the arm with a pencil. Great, I be had this b4 ez to test salt level.

• Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Temperature Compensation
• Measure salt water or salinity of water, ideal for aquariums and marine monitoring.
• Measures on 2 scales, Specific Gravity (D 20/20) and parts per thousand.
• Features automatic temperature compensation.
• Comes with hard case, dropper, screwdriver, user manual and cleaning cloth.
• The main part is made of chromium, it's very durable.
• Manufacture: Xin Da Cheng
• Product Dimensions: 2 x 3 x 8 inches; 8.8 Ounces

• Editor's Impressions Of The Agriculture Solutions WL0020-ATC
• Accuracy [star rating='5']
• Quality [star rating='5']
• Value For Money [star rating='4.8']
• Affordability [star rating='5']

10. 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']