SunGrow Refractometer for Saltwater Aquarium & Reef Tank, Koi Pond Water Salinity Meter Tester

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About This Item

Details

  • Refractometer specially designed for saltwater aquariums.
  • Measures the salt percentage and specific gravity in your tank.
  • Provides a clear and easy reading of your tank’s salinity and specific gravity.
  • Comes in a solid case that includes a pipette and a calibration tool.
  • Has automatic temperature calibration.

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4.5
Rated 4.5 out of 5 stars
32 Ratings
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15 Customer Reviews

Rated 5 out of 5 stars
By Harry on Jan 23, 2025

Works well

I had not used a refractometer since I was a chemistry student many years ago, so I bought this in part as a stroll down memory lane. For an inexpensive instrument

I had not used a refractometer since I was a chemistry student many years ago, so I bought this in part as a stroll down memory lane. For an inexpensive instrument this seems well made and works surprisingly well. For the best result it is important that the water you are testing and the water used to check the zero are as close to the same temperature as possible. To see the scale easily use the brightest light source you can. A clear sunny sky works well (don't look directly at the sun, of course). Used properly this should measure salinity better than any color changing kit.

Rated 5 out of 5 stars
By Ruben on Jul 30, 2025

Cheap

Cheap products but you get what you pay for!

Cheap products but you get what you pay for!

Rated 1 out of 5 stars
By Brandon on Jun 26, 2025

Damage

No instructions case cracked

No instructions case cracked

Rated 5 out of 5 stars
By Justin on Feb 25, 2025

Great tool! Highly accurate.

I use this regularly & find it highly accurate. Highly recommended.

I use this regularly & find it highly accurate. Highly recommended.

Rated 5 out of 5 stars
By Shannon on Nov 9, 2024

New gadget for me

We're doing our first brackish tank and need to maintain rather low levels of salinity. This made it fairly simple to test the water mix ahead of adding to the crab

We're doing our first brackish tank and need to maintain rather low levels of salinity. This made it fairly simple to test the water mix ahead of adding to the crab tank.

Rated 1 out of 5 stars
By Sarah on Aug 17, 2024

Does not work at all

The refractometer's case was smashed in shipping, so maybe the refractometer was damaged as well; however, it doesn't appear to have any obvious damage. No matter

The refractometer's case was smashed in shipping, so maybe the refractometer was damaged as well; however, it doesn't appear to have any obvious damage. No matter what I do I cannot see any white on the scale. I'll get the scale in focus (it's entirely blue), then look away for a second and it's out of focus again. I've used many refractometers while working in labs, but this one does not work at all.

Rated 5 out of 5 stars
By Werner on Sep 5, 2024

Easy and Accurate

Skeptical when I saw the price,,unit once calibrated with 0 TDS water(easy),is super accurate,I use 3 methods to check salinity,,Goin strong 7 months of use

Skeptical when I saw the price,,unit once calibrated with 0 TDS water(easy),is super accurate,I use 3 methods to check salinity,,Goin strong 7 months of use

Rated 1 out of 5 stars
By Carlton on Dec 2, 2024

Does not calibrate

I need to return

I need to return

Rated 5 out of 5 stars
By Andrew on Jan 1, 2025

Easy to use

Great price.

Great price.

Rated 5 out of 5 stars
By willy on Oct 2, 2023

Where have you been all my life?

I've been involved in saltwater fishkeeping for more than 30 years, with occasional breaks. During this time, I relied on a plastic salinity hydrometer, despite

I've been involved in saltwater fishkeeping for more than 30 years, with occasional breaks. During this time, I relied on a plastic salinity hydrometer, despite its flaws. It often disturbed the fish and could get messy, especially when it dried up and caused the floating needle to become stuck. I'd have to wet it and shake it to get it moving freely, but I still couldn't trust its accuracy. I had heard about the advantages of using a refractometer for salinity measurement, but I was initially put off by the belief that calibration would be a complex and demanding process, akin to handling laboratory equipment. However, I was proven wrong on all fronts. Calibration with the refractometer turned out to be a simple task - just a few drops of RO water on the glass, close the flap, look through the viewer, and adjust the screw until the line read zero. That was it. Using it was even more straightforward; you could test your tank water without the need for calibration. The entire process took just a few seconds. It's remarkably user-friendly, although you do need to hold it up to a well-lit area to get a clear reading. The blue line on the refractometer provides a precise measurement of salinity, eliminating the need for guesswork. I wholeheartedly recommend this tool for serious saltwater aquarium enthusiasts.