I have checked the AquaChek White salt test strips on numerous occasions against both a Taylor salt test kit and properly calibated salt meters (both Goldline and LaMotte) and am more than satisfied that this is one test strip that is actually worth it's salt! They have been right on the money each time! It IS important to allow enough time for the test to complete (As Poolsean said, 4-10 minutes or until the bar at the top is dark all the way across, my expreience has been around 10 minutes) and be sure to put them in no more than about an inch of water. Also, as Poolsean said, each bottle is individually calibrated so only use the scale on the bottle the strip came out of when checking your results or they won't be correct!