Our new refractometer has been receiving rave reviews from independent sources. Check out these links and our video which explains why our refractometer gives a true salinity reading for reef aquariums. One reason it is so important is that the salinity will affect the level of foundation elements and this will affect coral growth and coloration (not to mention you may be spending too much on salt by running a salinity which is higher than your current refractometer is leading you to believe). http://www.redseafish.com/red-sea-sa...salinity-test/ and for the independent reviews click here: http://reefbuilders.com/2014/05/14/r...rium-salinity/ and here http://digital-reefs.com/?p=8417