A short write up on common issues reefers face when mixing salt water. This article aims to covers a couple of areas: Consistency issues with large buckets of salt mix (top vs bottom) How optical refractometers work. Selecting the right refractometer. Calibration method Other processes that may adversely affect the water parameters (eg. Prepare salt for specific gravity of ~ 1.025. But when you measure the Ca, Mg, KH parameters, it’s NOT as per published numbers) Hand