MY MIRONEY 2-Pack Salinity Tester Sea Hydrometer Salinity Meter Specific Gravity Test for Aquarium Fish Tank Water Marine Saltwater

Ok so, if you’re relying solely on this as a measuring device, then that’s gambling. I have refractometers and an icecap salinity pen tester. But let me tell you why I keep buying these hydrometers. Cuz I don’t want to keep squinting after calibration, waiting for 45 sec for temp adjustment and squint for testing with refractometers. With pen testing they drift, and you don’t know when or why they drift. So I use those to get my salinity right on these hydrometers. I scoop test water, knock out the air bubbles and watch it. And when done, I empty and scoop RO water if not reading anything for the moment. When I’m done, I empty it and dry it sideways so the swing arm dries freely. These are consistent but the numbers are not accurate. So I marked my own. Hope this helps.