Editor's Choice - Our Favorite Rhinoco Aquarium Hydrometers

1. Rhinoco Salinity Refractometer, Saltwater Aquarium Refractometer, Dual Scales Specific Gravity Salin...

User Ratings: 75

Rhinoco RINTL277US First Impressions

"Great product!"

I bought this salinity meter for my aquarium. I will get one later but for now this will do, since im just starting. Get precise salinity readings in moments. Great, I be had this b4 ez to test salt level. Even the smallest bubble will throw the measurements way, way off. However, the numbers are soooo small it is sometimes hard to read. I compared the readings using this hygrometer and the calibrated refractometer.

• Rhinoco Salinity Refractometer, Saltwater Aquarium Refractometer, Dual Scales Specific Gravity Salinity Meter with 0-100 PPT and 1.000-1.070 for Seawater, Pool, Tank, Testing, Marine Fishkeeping
• 【Salinity Refractometer】Measure Salt Water or Salinity of Water, ideal for Aquariums, Marine Monitoring, Agricultural, Gardening & Educational Purposes.
• 【Automatic Temperature Compensation】Salinity Tester Built-in ATC, which Accounts for Changes in Ambient Temperature and Automatically Compensates Accordingly to Guarantee Consistently Accurate Readings.
• 【Dual Salinity Scale】Salinity Mester with Dual Scale 0-100 ppt(0 - 10 %) of Salinity and 1.000 to 1.070 Specific Gravity (0-10%).
• 【Full Copper Chrome Plated Design】Sturdy & Compact, the Eyepiece is in High Quality for Better Viewing, Adopting Optical Glass Lens Rather than Plastic Lens for Accurate Measurement.
• 【Accessories & Warranty】1 x Salinity Refractometer, 1 x Plastic Pipette, 1 x Mini Screw Driver, 1 x Cleaning Cloth and User Manual, Comes with 18-Month Warranty!
• Manufacture: Rhinoco

• Editor's Impressions Of The Rhinoco RINTL277US
• Accuracy [star rating='3.8']
• Quality [star rating='5']
• Value For Money [star rating='3.9']
• Affordability [star rating='4.5']

Here Are Some Other Related 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. 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']

4. Pet Dog Cat Refractometer Pet Urine Specific Gravity Refractometer Serum Plasma Protein: 2~14g/dl, C...

User Ratings: 66 16

RZ First Impressions

"Clear directions."

Trying to turn it by hand won't work. The water was at what I expected it should be. I would recommend this product to anyone that has a marine aquarium. The instant ocean hydrometer will always be right. And it is much more accurate than my old salinity meter. This requires repeatedly tapping the arm with a pencil. Bubbles can greatly affect the reading.

• Pet Dog Cat Refractometer Pet Urine Specific Gravity Refractometer Serum Plasma Protein: 2~14g/dl, Clinical Animal Refractometer Hydrometers Urine Tester 1.000-1.060SG for Veterinary Cat Dog Pets
• TRIPLE SCALES REFRACTOMETER: Left scale for testing urine specific gravity of large animals such as dog, the middle scale can measure cats urine specific gravity or other small animals, the right scale tests serum or plasma protein level for all animals.
• QUICK & EASY OPERATION: few sample than other lab hydrometers, just 2 or 3 drops of solution and wait for a few seconds, accurate data automatic shows, automatic temperature compensation 0°C-30°C/50°F to 86°F
• MEASURING RANGE: Serum or plasma protein: 2-14g/dl, large animal like dog and small animals like cats’ urine specific gravity 1.000~1.060 SG, resolution: 0.001SG. Ideal for your home pets, clinical veterinary and pet owners.
• DURABLE REFRACOMTER: comfortable holding and non-slip ABS rubberized grip, anti-rust aluminum body for long term using. Strictly quality and safety standards approved.
• COMPACT SIZE: Lightweight and pocket size lab refractometer, comes with sturdy plastic box, mini screwdriver, pipette and wiping cloth and manual packed together, easy to carry and storage.
• Manufacture: RZ

• Editor's Impressions Of The RZ
• Accuracy [star rating='4.5']
• Quality [star rating='5']
• Value For Money [star rating='4.7']
• Affordability [star rating='3.9']

5. 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']

6. 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']

7. 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']

8. KOOBOOK 1 Pcs Accurate Hydrometer Salinity Meter 1.000-1.027 Salinity Range 0-36 for Aquarium Fish T...

User Ratings: 44 27

KOOBOOK First Impressions

"0, it reads 1."

Not sure how accurate it is, but it's a good reference point. I will get one later but for now this will do, since im just starting. It is heavy and easy to read in any light. Find a good light source to make reading easier. It works, we'll i assume it does as i have nothing to compare it to. If you read the directions in the box for the refractometer it's for freshwater. Good quality and simple to use refractometer.

• KOOBOOK 1 Pcs Accurate Hydrometer Salinity Meter 1.000-1.027 Salinity Range 0-36 for Aquarium Fish Tank Marine Sea Saltwater
• Made of high quality plastic, Withstand voltage,high transparency.
• Special for culture of marine fish, the specific gravity and salinity of seawater are displayed once, easy to use and easy to read.
• Keeping your hands clean,go underwater 15 cm (6 inch) depth to avoid errors caused by inhalation of oil film on the top of water.
• When the water reaches full state (with the top of the baffle level), filed a hydrometer, this product can be hand or hang in the cylinder, automatic level function, can automatically find out the level to avoid the error.
• Proper salinity level is one of the most important factors in the health of the fish.Readable and accuracy can up to ± 0.002 gravity unit.
• Manufacture: KOOBOOK

• Editor's Impressions Of The KOOBOOK
• Accuracy [star rating='2.7']
• Quality [star rating='2.8']
• Value For Money [star rating='2.7']
• Affordability [star rating='2.7']

9. LemonBest 0%-10% Automatic Temperature Compensation Salinity Refractometer Salt Water Aquariu...

User Ratings: 75 5

LemonBest First Impressions

"Great tool."

I don't want to deal with temperature correction or. When I compared it to what my local pet store was reading my water at it was dead on. Used distilled water to calibrate, the screw is located under the rubber cap. This one here was much cheaper,& exactly the same as they sold in the store. At first, I was getting bubbles sticking to the rotating arrow. Definitely a lot cheaper than a refractometer. I decided to upgrade and it was easy to calibrate.

• LemonBest 0%-10% Automatic Temperature Compensation Salinity Refractometer Salt Water Aquarium by Lemonbest
• Features with automatic temperature compensation (ATC) function
• Designed for testing the concentration of salt water and brine, ideal for aquariums, marine monitoring and quality control in research and clinical laboratories
• With just a couple of drops of aquarium water you know exactly what the salinity is
• Measures on 2 scales, specific Gravity (D 20/20) and parts per thousand (‰), provides a direct reading of the specific gravity and concentration of salt in water
• Comes with a hard case, dropper, screwdriver and cleaning cloth
• Manufacture: Lemonbest
• Product Dimensions: 7.87 x 1.57 x 1.57 inches; 3.88 Ounces

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

10. Aichose Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium, Saltwater Pool, with AT...

User Ratings: 71

aichose SR0024BE First Impressions

"Easy to use."

I use this for my 10g brackish and it works ok. I was surprise that the product was really cheap compare to the other ones. Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. 010; I can easily read this off of the refractometer. 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. It did not need adjusting to calibrate, though I tried to just to see how it worked.

• Aichose Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium, Saltwater Pool, with ATC Function, Dual Scale: Salinity 0-100‰ and Corresponding Specific Gravity
• It is designed for the measurement of seawater or low concentrated saltwater.
• Dual scale: 0-100‰ salinity and corresponding specific gravity 1.000-1.070
• Automatic temperature compensation function minimizes the effect of the temperature on testing result.
• Easy to Use: It's very easy to use even for new users. And no battery needed.
• Ideal for marine fishkeeping aquarium, saltwater pool, marine monitoring,lab,agricultural, gardening and educational purposes.
• Manufacture: XDC Co,.Ltd.

• Editor's Impressions Of The aichose SR0024BE
• Accuracy [star rating='4.4']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.3']