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
  • Quality
  • Value For Money
  • Affordability

Fluval 14356 Final Thoughts

"Works great for reefing!"

Great tool if you have a salt-water fish tank or a decorative pond. I strongly recommend a refractometer vs. It works, we'll i assume it does as i have nothing to compare it to. Definitely a lot cheaper than a refractometer. Great product I used for beer making and my saltwater aquarium. It came with all that was listed in the in production description. Plenty of info on YouTube and the web if you don't know how.

Overall Score
3.7


(373 Points)

2. ZRM&E Seawater Hydrometer for Aquarium Aquaculture Seawater Densimeter Ocean Hydrometer Salinity Met...

User Ratings: 70 30

ZRM&E First Impressions

"Gave me confidence."

YOU WILL NOT get an accurate reading if there are bubbles on the needle. I have purchased before will buy again! I felt it wasn't accurate which was verified by my LFS. Very quick to calibrate and to use. It says in the instructions to use distilled water. I bought this refractometer as a more accurate option for salinity than a hydrometer. Don't spend your money on calibration solution.

  • ZRM&E Seawater Hydrometer for Aquarium Aquaculture Seawater Densimeter Ocean Hydrometer Salinity Meter for Fish Tank Salinity Specific Gravity Test
  • Made of high quality plastic, aquarium transparent, automatic accurate reading brine hydrometer
  • Accurate, durable and easy to read salt and specific gravity of your marine aquarium, small and waterproof. If the specific gravity is between 1.000-1.019, it indicates that the specific gravity is low; if the specific gravity is between 1.020-1.023, it indicates that the specific gravity is normal; if the specific gravity is between 1.024-1.030, it indicates that the specific gravity is high
  • The external range of the scale indicates salinity (PPT), and the internal range of the scale indicates gravity. And clearly mark the safe area. Application range: 0-40 degrees (1.000-1.030). If the salinity PPT is between 32-40, it indicates that the salinity is high; if the salinity PPT is between 27-31, it indicates that the salinity is normal; if the salinity PPT is between 0-26, it indicates that the salinity hydrometer is low
  • Wide range of applications: Suitable for salt water and sea water fish tanks. Perfect for testing salinity and specific gravity of saltwater and seawater tanks, including solubility and specific gravity scales. Suitable for fresh water and sea water
  • Easy to read swing arm pointer and ultra wide stable base can provide accurate test results
  • Manufacture: DGHP
  • Editor's Impressions Of The ZRM&E
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

ZRM&E Final Thoughts

"Great Product, Thanks!"

YOU WILL NOT get an accurate reading if there are bubbles on the needle. Get precise salinity readings in moments. If you let it sit in the tank overnight, it definitely gives an accurate reading. Compare it with the refractometer and adjust the refractometer so that it matches. Don't care much for having to post a review in order to activate warranty. Even the smallest bubble will throw the measurements way, way off. I would recommend this product to anyone that has a marine aquarium.

Overall Score
3.8


(4 Points)

3. 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
  • Quality
  • Value For Money
  • Affordability

amzdeal Final Thoughts

"Massive peace of mind."

Be sure to adjust the focus by turning the eye focal when you first receive. Even the smallest bubble will throw the measurements way, way off. YOU WILL NOT get an accurate reading if there are bubbles on the needle. I use this to check the specific gravity of my marine aquarium. When I saw the price offered on this one, I decided to buy and I love it. Excellent piece of equipment for the price. Perfrct for someone learning or anyone for that matter.

Overall Score
4.2


(56 Points)

4. 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
  • Quality
  • Value For Money
  • Affordability

Ade Advanced Optics aaosal Final Thoughts

"Arrived quickly."

This requires repeatedly tapping the arm with a pencil. On the shaft of the refractometer, there's a little, rubber-covered nub. However, the numbers are soooo small it is sometimes hard to read. I have tried others before but this has given me accurate and stable results. I would suggest purchasing the salt calibration solution. It's fast, it's tidy, and it's accurate. When I compared it to what my local pet store was reading my water at it was dead on.

Overall Score
4.5


(9 Points)

5. 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
  • Quality
  • Value For Money
  • Affordability

Aeroway 8541957182 Final Thoughts

"Works great!"

Simple to use, but if there are any air bubbles the results will be way off. I compared the readings using this hygrometer and the calibrated refractometer. Normally that gives the more accurate reading. It's a basic but reliable refractomer I use it for my aquariums. Every time I leave to do something I come back and it's at the bottom of my tank. I bought this and a hydrometer because of the reviews saying its not accurate. So worth it considering its great quality and great price.

Overall Score
4.6


(43 Points)

6. 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
  • Quality
  • Value For Money
  • Affordability

KOOBOOK Final Thoughts

"This tool does that."

It works, we'll i assume it does as i have nothing to compare it to. But with alittle persistance I am able to read it. I have purchased before will buy again! I have to recalibrate it ever use though which worries me sometimes. This requires repeatedly tapping the arm with a pencil. I would suggest purchasing the salt calibration solution. The reading is big enough for you to read and it comes with the batteries.

Overall Score
3.3


(11 Points)

7. Bubble Magus Digital Color Screen Salinity Meter

Bubble Magus First Impressions

"Good value."

YOU WILL NOT get an accurate reading if there are bubbles on the needle. Every time I leave to do something I come back and it's at the bottom of my tank. On the shaft of the refractometer, there's a little, rubber-covered nub. However, the numbers are soooo small it is sometimes hard to read. Just rinse with warm water afterwards. I use this for my 10g brackish and it works ok. Bought this as a back up refractometer.

  • Bubble Magus Digital Color Screen Salinity Meter
  • Manufacture: Bubble Magus
  • Editor's Impressions Of The Bubble Magus
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

Bubble Magus Final Thoughts

"Easy to use."

Functions just as it is supposed to. Be sure to buy the calibration solution and test this before use! Ambient room light at night is not enough and makes what you're viewing dark. It is a little cheaper made but it works great for the cost! I decided to upgrade and it was easy to calibrate. I would recommend this product to anyone that has a marine aquarium. So worth it considering its great quality and great price.

Overall Score
5.0


(1 Points)

8. Ade Advanced Optics aaosal-B Automatic Temperature Compensation Sea Water Salinity Refractometer for...

User Ratings: 26 41

Ade Advanced Optics aaosal-B First Impressions

"Be well my friend."

Comes with a nice carrying case for easy and secure transportation. I have gone two years in this hobby with a hydrometer. It says in the instructions to use distilled water. Good quality and simple to use refractometer. The refractor was off out off the box. It is heavy and easy to read in any light. I use this for my 10g brackish and it works ok.

  • Ade Advanced Optics aaosal-B Automatic Temperature Compensation Sea Water Salinity Refractometer for Aquarium, 0% - 10% and 1.0 to 1.070 S.G. Dual Scale Hydrometer, Black
  • Manufacture: Ade Advanced Optics
  • Editor's Impressions Of The Ade Advanced Optics aaosal-B
  • Accuracy
  • Quality
  • Value For Money
  • Affordability

Ade Advanced Optics aaosal-B Final Thoughts

"Couldn't be happier."

Would be nice if stem were slightly larger for easier read. Looks to provide very accurate readings. Works well on my Saltwater Aquarium. I've tried several different refractometers now and they are mostly the same. 027, I'm so glad I bought this one and it came spot on. I use this to check the specific gravity of my marine aquarium. I felt it wasn't accurate which was verified by my LFS.

Overall Score
3.0


(4 Points)

9. 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
  • Quality
  • Value For Money
  • Affordability

Gain Express 837-2 Final Thoughts

"So, it does seem to work."

But with alittle persistance I am able to read it. Perfrct for someone learning or anyone for that matter. Once I adjusted the refractometer, my aquarium salinity read 1. Works great,& comes in a storage box. Works well on my Saltwater Aquarium. It did not need adjusting to calibrate, though I tried to just to see how it worked. Would be nice if stem were slightly larger for easier read.

Overall Score
3.8


(99 Points)

10. 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
  • Quality
  • Value For Money
  • Affordability

V·RESOURCING VLT065 Final Thoughts

"Massive peace of mind."

I HIGHLY recommend this to Aquarists! I will update later to see if the refractor will keep its calibration. When I saw the price offered on this one, I decided to buy and I love it. Pretty darn accurate for the price. Too that makes it appear too cheap. Small problem with bubbles on the needle but other than that no issues. Bubbles can greatly affect the reading.

Overall Score
4.7


(28 Points)

Copyright © 2021 Rob Aquatics — Primer Child WordPress theme by GoDaddy