I know the hydrometer is know to be inaccurate but would it be possible for it to be off by .005 points. When I was setting everything I was being lazy and just nh used the hydrometer and I finally checked the salinity with the refractometer. The hydrometer said it is 1.025 and the refractometer says its 1.030 so would it be possible to be off bu that much? And yes I checked calibration with zero TDs ro water.