Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Temperature Compensation

This is a great product! The readings are accurate and very easy to read, even for beginners. The instructions included were clear and helpful, making setup and calibration simple. It also comes with a strong, protective case that keeps the refractometer safe when not in use — a really nice touch for long-term durability. Absolutely no complaints here. Highly recommend for anyone working with seawater or saltwater aquariums.

About a month ago, I was down to zero Sea Monkeys. I siphoned out about 75% of the water and ran it through a coffee filter, then let the tank sit.A week later—surprise! Hatchlings. These eggs were clearly dormant and just waiting for the right moment. Only two made it to adulthood, but I kept seeing new babies that didn’t survive past the first week.Today, I tested the salinity with this refractometer and found it was too low: 1.008. To fix it, I made a 1-ounce concentrate of kosher (non-iodized) salt water and added it slowly using a pipette, checking levels along the way. I brought the salinity up to 1.015, which put both the salt level and water level right where they should be.Since evaporation could raise it naturally to 1.016–1.017, I’m now in the ideal range for adult Sea Monkeys. I’m hopeful the six babies I see now will finally make it past the critical first week- and I’m pretty sure the adults feel like they’ve just come back from a spa day.

Durable and easy to use . Accurate readings

Great product fast shipping

The directions even tell you so. It needs to be calibrated pretry much before every use. I use calibration fluid and then verify by checking distilled water. I has to tune mine down about .12 for it to be correct. Only giving 4 stars because deoending on how the light is shining into it, it can be tricky to read.

Very accurate old school reliability!

This thing was so inexpensive and it seems to be accurate. Only thing is that it loses calibration quickly. Not sure why. Does the screw come loose just sitting in the case? I just calibrate it quickly with some calibration solution. Kinda annoying, but hey this thing was so inexpensive.

My fish are happy and healthy. I was scared that this would be hard to use since I just started keeping fish, but it is very simple and easy. I don’t know how easy it would be to use with glasses, but I couldn’t say. Very quick and definitely more trustworthy than other brands.