Review on 🐠 RZ Aquariums Salinity Refractometer: Accurate Dual-Scale Hydrometer for Marine Fish-Keeping, ATC Function, Saltwater Tester 0-100ppt & 1.000-1.070 Specific Gravity by Agustin Bush

Specialty Aquarium Calibration Fluid 1.026 must be purchased and adjusted to this level. Otherwise, the device can be disabled easily enough to cause damage, especially when adding livestock. Animals can adapt to higher or lower salinity levels in your tank over time, but if you think you have 1.026 and your tank doesn't, new animals will be shocked. Check the bagged water for new animals and acclimate - if you do this you'll know what the drift is, but the refractometer needs to be calibrated for maintenance.