Seawater Refractometer

Great service works good

After using it multiple times. Then checking the calibration. It seems to stay consistent. Definitely worth the purchase.

Great item makes checking salt levels super easy

Everything is perfect with this, it’s not pricey and does the job

This refractometer is easy to read. The contrast between the dark blue and white indication is vastly superior to any of the competition in this price range that have an "atc" stamped on them.

Not very useful for pool salt readings [2700ppm to 3500ppm] - reading a value of 3ppt [3000ppm] on the scale of 0-100ppt looking through an eyepiece, is just nonsense.

Good all

This loses calibration so fast that 1) you need to calibrate it with 35ppt calibration solution before EVERY use, and 2) it loses calibration so fast that you can't even trust the sample readings you get after calibration sometimes. Definitely don't trust it if you're calibrating to 0 ppt with distilled water. I would only consider using it if you immediately calibrate to 35ppt with 35ppt sea water calibration solution right before taking your aquarium test. I ran back to back tests with the same 35ppt calibration solution - cleaning with distilled water between tests - and 2nd test was already getting close to drifting 1 ppt lower than first test. And if you've had it sitting around a couple hours or a day, you're likely to be 3 or 4 ppt off from previous calibration. I'm guessing It's an okay tool if what you want to do is compare your tank water to your water change water and will be testing the tank and then immediately testing the water change water and just looking to see if they're the same. But with how quickly it changes its calibration, I don't put much trust in the actual number reading you get, unless you're okay being up to 3 ppt off. (which I would say is not an acceptable deviation).