Hydrometers & Refractometers

At AquaCave, we offer some of the best selection & best prices on Salinity Refractometers and Hydrometers for you marine, reef, and freshwater aquarium.
Refractometers are precision optical instruments used for measuring aquarium water salinity. They work using principle of light refraction through liquid. When passing light through a liquid the refracted angle will be shown on the scale determining the amount of salt in the water. Very easy to use; simply place one drop of water on the prism and read the results on the scales immediately. They have adjustable focus, easy to read numbers for good resolution, and zero adjustment screw for calibration. These refractometers have Automatic Temperature Compensation feature and are suitable for application where the temperature of the samples vary.