Editor's Choice - Our Favorite Fluval Aquarium Hydrometers

1. 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']

Here Are Some Other Related Aquarium Hydrometers

2. 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']

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. Pen Type Salinity & Temp Meter Measurement Units Checker Quality Tester ATC for Pond Pool Saltwater ...

User Ratings: 36 25

TEKCOPLUS SMTK-49_SOL First Impressions

"So here's the verdict."

Just give me one simple, accurate reading to go by, and I'm happy. This is perfect to keep a check on the salt level in your tank. He is too cute not to want to take care of properly. Bought this as a back up refractometer. Get precise salinity readings in moments. The unit is really easy to calibrate and used. My only criticism would be that it's a little too dark.

• Pen Type Salinity & Temp Meter Measurement Units Checker Quality Tester ATC for Pond Pool Saltwater Aquarium Cooking Seawater Drinking Water (Salinity Meter 70.0ppt + Buffer Sol'n)
• Ideal for checking salt in fish tanks and aquariums, water monitoring, seawater-prepared food solutions, holding tanks and more!
• Measuring Range: Salinity: 0.00~10.0 ppt (NaCL) and 10.1~70.0ppt (NaCL)
• Auto Power-Off Function with disable feature
• °C/°F unit switchable ,Easy one-touch calibration, Waterproof Rating: IP65
• Calibration set: Buffer NaCI 50ppt and calibration guideline
• Manufacture: TekcoPlus Ltd

• Editor's Impressions Of The TEKCOPLUS SMTK-49_SOL
• Accuracy [star rating='3.8']
• Quality [star rating='3.8']
• Value For Money [star rating='2.6']
• Affordability [star rating='3']

5. Coralife BioCube Mini Aquarium Hydrometer

User Ratings: 37 28

Coralife 100115642 First Impressions

"NO BUBBLES!"

My corals will be much happier now. Every time I leave to do something I come back and it's at the bottom of my tank. 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 is a little cheaper made but it works great for the cost! Just give me one simple, accurate reading to go by, and I'm happy. When I saw the price offered on this one, I decided to buy and I love it.

• Coralife BioCube Mini Aquarium Hydrometer
• Can remain submerged inside your aquarium or sump
• Know your salinity in a glance
• Compact design allows for discreet placement in the aquarium
• Ideal for all saltwater aquariums and sumps
• Manufacture: Central Garden & Pet
• Product Dimensions: 3.9 x 1 x 6 inches; 0.8 Ounces

• Editor's Impressions Of The Coralife 100115642
• Accuracy [star rating='3.4']
• Quality [star rating='4.3']
• Value For Money [star rating='2.8']
• Affordability [star rating='3.9']

6. 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']

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. 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']

10. 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']