screw refractometers man!!! Me and Dbarsotti were both fed up with inconsistent resulsts and we are now both using coral sea swing arm hydrometers hahaha. Both of our tanks are doing very well! They're dead on every time. I cross referenced mine with a calibrated refract and it was basically the same reading. Only thing that is really crucial is that you must have no air bubbles on the arm and you're all set. I just did a water change today using my trusty hyrdrometer and everything is looking better than ever lol.
The only problem with them is that over time calcium builds up on the swing arm giving an incorrect reading.
