Don’t settle for "close enough" when it comes to your reef’s salinity. Most hobbyist refractometers are designed for Brine (Sodium Chloride), which can lead to measurement errors of up to 1.5ppt. The Red Sea Seawater Refractometer is engineered specifically for the complex ionic content of Natural Seawater, providing the "Absolute Salinity" readings your corals need to thrive.
| Feature | Details |
| Calibration Solution | Natural Seawater (NSW) / Red Sea 35ppt Fluid |
| Calibration Temp | 25°C / 77°F |
| Range | 0 – 40 ppt (High-Resolution Scale) |
| Accuracy | $\pm$ 1ppt / 0.001 S.G. |
| ATC Range | 10°C – 30°C (50°F – 86°F) |
| Includes | Protective Carry Case, Pipette, & Calibration Screwdriver |
Inconsistent salinity is a leading cause of coral stress and RTN (Rapid Tissue Necrosis). By using a tool specifically calibrated for 25°C/77°F, you ensure that your salt, alkalinity, and calcium levels are perfectly balanced, as these parameters all drift when salinity is measured incorrectly.
Clean: Clean the prism with RODI water and dry with a soft cloth.
Apply: Apply a few drops of RODI water for zeroing.
Wait: Wait 15 seconds for the temperature to equalize (Integrated ATC).
Adjust: Look through the eyepiece and adjust the calibration screw until the line meets the 35ppt/1.0264 mark exactly.
Q: Why is "Absolute Salinity" better than standard SG?
A: Standard refractometers are calibrated for salt brine at 15°C. Red Sea’s algorithm accounts for the 70+ trace elements in seawater at reef temperatures (25°C), preventing the common 1.5ppt measurement error.
Q: Can I use this for a freshwater tank?
A: While it will work, the 0–40ppt scale is optimized for high-resolution marine readings, giving you 2.5x the visual clarity of standard 0–100ppt scales.
Red Sea Coral Pro Salt: Designed to work hand-in-hand with this refractometer’s calibration.https://petstore.ae/collections/salt-mix-maintenance/products/red-sea-coral-pro-salt-black-bucket?_pos=3&_sid=d608880c5&_ss=r
Red Sea Foundation Care Program: Monitor the Calcium and Alk levels that rely on stable salinity.https://petstore.ae/collections/reef-restoration/products/redsea-4-part-complete-reef-care-dosing-system?_pos=1&_sid=7253a0301&_ss=r
Seawater Analytical Standard: High-precision 35ppt calibration fluid for monthly checks.https://petstore.ae/products/vastocean-precision-salinity-35ppt-calibration-solution-professional-grade-standard-for-marine-aquariums?_pos=14&_sid=d2890dc27&_ss=r
