Refractometer Reagents Calibration Standard 60ml 1.0264 Specific Gravity1.3394 Refractive Index35 ppt Salinity53 uS/cm at 25 deg c Overview Brightwell Aquatics Aquarium Reagents Refractometer Calibration Standard is designed to provide an accurate reference for the calibration of seawater refractometers, hydrometers and other density measuring equipment. Sizes 60ml Instructions & Guidelines - Refractometers 1. Shake product well before using.2. Clean Refractometer prism slide with fresh distilled water.3. Dry completely with soft clean dry cloth.4. Place several drops of Brightwell Refractometer Calibration Standard fluid on the slide.5. Wait 45 seconds and calibrate to 35 ppt Salinity. Brightwell Aquatics Refractometer Calibration Standard 60ml, Brightwell Aquatics available at the best price to buy now at Kraken Corals & Aquatics