Editor's Choice - Our Favorite KKmoon Aquarium Hydrometers

1. KKmoon Salinity Refractometer, Handheld Seawater Hydrometers, Optical Salinity Tester, Portable ATC ...

User Ratings: 70 8

KKmoon First Impressions

"Decent case."

Hate the batteries, but once loaded, it seems to work fine. Get precise salinity readings in moments. I have a 2000+ gallon pond and I just put salt in it last month. The hydrometer is good, but I ordered two Shrimp CRS Miniature glass figurine, Clear. So once your instant ocean shows a measurement. All very easy and I feel as though I am getting an accurate salinity reading. The reading is big enough for you to read and it comes with the batteries.

• KKmoon Salinity Refractometer, Handheld Seawater Hydrometers, Optical Salinity Tester, Portable ATC Refractometer, Dual Scale Saltwater Tester for Aquarium, Seawater, Pool, Fish Tank
• Measure salt water or salinity of water, ideal for aquariums and marine monitoring.
• With measurement level for direct reading. Adjustable manual focus, easy to focus and calibrate.
• Handheld design and non-slip rubber handle for easy operation.
• Instant Reading Result: Just need 2-3 drops of solution and a few seconds, you can get accurate readings.
• Built-in automatic temperature compensation(ATC) to get faster results.
• Manufacture: KKmoon
• Item Weight: 8.9 ounces

• Editor's Impressions Of The KKmoon
• Accuracy [star rating='4.4']
• Quality [star rating='4']
• Value For Money [star rating='3.8']
• Affordability [star rating='4.8']

Here Are Some Other Related Aquarium Hydrometers

2. Automatic Temperature Compensation Sea Water Salt Salinity Refractometer for Aquarium, 0% - 10% & 1....

User Ratings: 50 10

Ade Advanced Optics Salinity10 First Impressions

"No assembly required."

I use this for my 10g brackish and it works ok. Like that it comes with everything needed. It is essential to get some specialized aquarium calibration fluid for 1. Looks to provide very accurate readings. I was surprise that the product was really cheap compare to the other ones. It is essential to get some specialized aquarium calibration fluid for 1. Hate the batteries, but once loaded, it seems to work fine.

• Automatic Temperature Compensation Sea Water Salt Salinity Refractometer for Aquarium, 0% - 10% & 1.0 to 1.070 S.g. Dual Scale Hydrometer By Adeadvancedoptics
• Manufacture: Ade Advanced Optics®
• Product Dimensions: 8.7 x 2.8 x 1.42 inches; 6.4 Ounces

• Editor's Impressions Of The Ade Advanced Optics Salinity10
• Accuracy [star rating='4']
• Quality [star rating='4.9']
• Value For Money [star rating='3.3']
• Affordability [star rating='3.2']

3. Accurate Automatic Hydrometer Salt Water Salinity Meter Salinimeter for Fish Tank (Square Type)

User Ratings: 63 16

YOSOO123 First Impressions

"Seems to work fine."

It is a little cheaper made but it works great for the cost! Now that it's calibrated I love it! I got this to have a more accurate read than the hydrometer. I decided to upgrade and it was easy to calibrate. I will get one later but for now this will do, since im just starting. Now that it's calibrated I love it! Plus it is super easy to use and clean.

• Accurate Automatic Hydrometer Salt Water Salinity Meter Salinimeter for Fish Tank (Square Type)
• 15 centimeters (6 inches) from the bottom of the water to avoid the error caused by the oil film on the water.
• Keeping your hands clean and can prevent pollution of water from the fish pond.
• It is easy to read and the precision can be + (-) 0.001 units of specific gravity. Professional design make it able to get accurate reading when the temperature of the fishpond is at 18 degrees -28 degrees
• Fish pool, both inside and outside the cylinder can be read. The hydrometer that can float on the surface of the water is simple and easy to read.
• The proportion of water sample can be automatically detected. The proportion, salinity and conductivity of sea water are shown once.
• Manufacture: Yosoo123
• Part Number: Yosoo537gtqix12
• Item Weight: 3.24 ounces
• Product Dimensions: 5.51 x 3.54 x 0.79 inches
• Style: Square Type
• Batteries Included?: No
• Batteries Required?: No

• Editor's Impressions Of The YOSOO123
• Accuracy [star rating='4.2']
• Quality [star rating='4.4']
• Value For Money [star rating='3.4']
• Affordability [star rating='4.5']

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

User Ratings: 66 12

amzdeal First Impressions

"Seems to work fine."

Hate the batteries, but once loaded, it seems to work fine. For the price you definitley cant beat this meter is great! I would recommend this product to anyone that has a marine aquarium. Make sure to knock out the bubbles on the white dial by hitting it with your knuckle. I was surprise that the product was really cheap compare to the other ones. I don't want to deal with temperature correction or. This is perfect to keep a check on the salt level in your tank.

• Amzdeal Salinity Refractometer Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.)
• 【Automatic Temperature Compensation】 Hand-held ATC refractometer, can be used in the temperature 5-30 ℃ / 41-86℉
• 【Dual Salinity Scale】Salt content 0 ~ 100 ‰ (0 ~ 10%) and Salt specific gravity 1.000 ~ 1.070sg. Minimum scale is 1 ‰ (0.1%) or 0.001sg, more precise
• 【Easy to Use】Using distilled water to calibrate and then you can measure the saltwater and get the result
• 【Package Content】Come with all the accessories, including Dropper, Screwdriver, Cleaning Cloth, Storage Case and User Manual
• 【Widely Use】This refractometer can be used to measure the salt content or sugar content, good for aquariums and marine monitoring
• Manufacture: Amzdeal

• Editor's Impressions Of The amzdeal
• Accuracy [star rating='4.7']
• Quality [star rating='4.8']
• Value For Money [star rating='4.1']
• Affordability [star rating='5']

5. KKmoon Salinity Refractometer, Handheld Seawater Hydrometers, Optical Salinity Tester, Portable ATC ...

User Ratings: 70 8

KKmoon First Impressions

"Decent case."

Hate the batteries, but once loaded, it seems to work fine. Get precise salinity readings in moments. I have a 2000+ gallon pond and I just put salt in it last month. The hydrometer is good, but I ordered two Shrimp CRS Miniature glass figurine, Clear. So once your instant ocean shows a measurement. All very easy and I feel as though I am getting an accurate salinity reading. The reading is big enough for you to read and it comes with the batteries.

• KKmoon Salinity Refractometer, Handheld Seawater Hydrometers, Optical Salinity Tester, Portable ATC Refractometer, Dual Scale Saltwater Tester for Aquarium, Seawater, Pool, Fish Tank
• Measure salt water or salinity of water, ideal for aquariums and marine monitoring.
• With measurement level for direct reading. Adjustable manual focus, easy to focus and calibrate.
• Handheld design and non-slip rubber handle for easy operation.
• Instant Reading Result: Just need 2-3 drops of solution and a few seconds, you can get accurate readings.
• Built-in automatic temperature compensation(ATC) to get faster results.
• Manufacture: KKmoon
• Item Weight: 8.9 ounces

• Editor's Impressions Of The KKmoon
• Accuracy [star rating='4.4']
• Quality [star rating='4']
• Value For Money [star rating='3.8']
• Affordability [star rating='4.8']

6. 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 [star rating='3.9']
• Quality [star rating='3.4']
• Value For Money [star rating='4.9']
• Affordability [star rating='5']

7. 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']

8. 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']

9. HydroLogic HLTDS DM-2 Industrial Monitor

HydroLogic HLTDS First Impressions

"Case is nice as well."

Don't care much for having to post a review in order to activate warranty. YOU WILL NOT get an accurate reading if there are bubbles on the needle. The water was at what I expected it should be. However, the numbers are soooo small it is sometimes hard to read. Get precise salinity readings in moments. Was calibrated and worked perfect right out of the box. I would suggest purchasing the salt calibration solution.

• HydroLogic HLTDS DM-2 Industrial Monitor
• Measures The Flow Of Untreated Water Coming In Versus Purified Water Going Out
• Comes Equipped With A 1/2" Inlet And 3/8Th Inch Outlet
• Features An Auto-Off Function To Conserve Battery Power
• No Assembly Required
• Manufacture: Hydro-Logic
• Item Weight: 2.38 pounds
• Product Dimensions: 7.2 x 5.1 x 1.7 inches

• Editor's Impressions Of The HydroLogic HLTDS
• Accuracy [star rating='4.3']
• Quality [star rating='5']
• Value For Money [star rating='4.5']
• Affordability [star rating='4.7']

10. Premium Salinity Refractometer with Automatic Temperature Compensation for Saltwater, Aquarium, Mari...

User Ratings: 75 9

ONE250 First Impressions

"Arrived quickly."

I HIGHLY recommend this to Aquarists! Find a good light source to make reading easier. But with alittle persistance I am able to read it. My corals will be much happier now. I would recommend this product to anyone that has a marine aquarium. It's perfectly accurate based on the known calibration fluid. When I compared it to what my local pet store was reading my water at it was dead on.

• Premium Salinity Refractometer with Automatic Temperature Compensation for Saltwater, Aquarium, Marine Reef Tank Testing - Dual Scale (0-100ppt & 1.000 to 1.070 S.G.)
• ✔ Hand-held analog salt meter; Light-weight, portable, includes protective carrying case
• ✔ Measures concentration of salt and dissolved solids in aqueous solution
• ✔ Provides reading in parts per thousand (0-100PPT) and specific gravity (1.000 to 1.070 SG)
• ✔ Ideal for on-site measurements in processing and storage areas, or in the field
• ✔ Determine salinity during preparation of pickles, seafood products, frozen vegetables and fruits
• Manufacture: ONE250
• Product Dimensions: 8 x 3 x 2 inches; 9.14 Ounces

• Editor's Impressions Of The ONE250
• Accuracy [star rating='4']
• Quality [star rating='5']
• Value For Money [star rating='5']
• Affordability [star rating='4.2']