Salinometer

A salinometer in aquaculture is a device used to measure the salinity of water, that is, the concentration of dissolved salts, mainly sodium chloride (NaCl). This measurement is essential in aquaculture because salinity directly affects the health, growth, and reproduction of aquatic organisms (fish, shrimp, mollusks, etc.).

Description

Main function:

• Measures water salinity (expressed in ‰ or ppt – parts per thousand, or PSU – practical salinity units).

• May also indicate density or electrical conductivity, both related to salinity.

Types of salinometers:

1. Manual (refractometer):

   • Uses light refraction through saline water.

   • Compact and easy to use.

   • Requires regular calibration.

2. Electronic (digital):

   • Often measures electrical conductivity.

   • More accurate, fast, often includes temperature compensation.

   • Can be portable or continuously installed in tanks (probes).

Common features:

• Waterproof.

• Measurement range adapted to fresh, brackish, or seawater.

• Digital display or visual scale.

• Calibration capability for accuracy.

Use in aquaculture:

• Monitoring culture tanks, storage reservoirs, and breeding zones.

• Helps prevent osmotic stress in species sensitive to salinity changes.

• Essential in marine and brackish water farming (e.g., shrimp, sea bass, sea bream)