📐
Testing
Refractometer
A precision instrument that measures salinity via light refraction - the reef-industry standard, more accurate than hydrometers.
Price: Mid
For: Saltwater Essential gear $40-$200
📖 Overview
A refractometer measures how much water bends light - a property directly proportional to dissolved salt. Place a drop of tank water on the prism, close the lid, and look through the eyepiece; the salinity reads on a marked scale. Refractometers must be calibrated with pure RO/DI water (0.0 ppt) or standard reference solution (35 ppt). Accurate to ±1 ppt with proper calibration.
🏷️ Top Brands
Milwaukee, Hanna Instruments, VeeGee.