About Salinity

Salinity is a general term that describes the concentration of salt in water. However different types of salt solutions have different indexes of refraction.

Brine is a solution of Sodium Chloride which contains 2 chemical elements.

Seawater contains approximately 70 chemical elements including Calcium, Magnesium, Potassium, etc… in addition to Sodium Chloride.

Seawater and brine with the same salinity (so the same number of grams of salt per liter of water) have different refractive indices and will give different salinity readings on the same refractometer.

Red Sea Saltwater Refractometer Key Features:

Direct reading of the absolute salinity of seawater at 25°C (no need for seawater or temperature compensation factors).

Specially developed for the ionic content of seawater for more accurate salinity measurement (industrial refractometers are calibrated for brine).

Calibrated for sea water at 25°C, normal temperature for a reef aquarium (most standard refractometers are calibrated at 15°C).

Easy-to-read, high-resolution display focused on useful reef aquarium values ​​up to 40 ppt.

Automatic Temperature Compensation (ATC) for accurate measurement at room temperature.

The ppt scale of the Red Sea seawater refractometer is calculated using a seawater algorithm and will therefore give you the Absolute Salinity of your seawater.

The ppt scale of conventional refractometers is calculated using an algorithm for brine. Using such refractometers will give you an error of about 1.5 ppt.