I just received the HI 96822 Seawater Refractometer from the contest. I always thought my standard refractometer did the job just fine until this week when I evacuated Hurricane Irma with my fish in tow. Setting up the tank at night with low lights made the job difficult with my old refractometer. I set this machine up today, took less than 5 minutes, and wow - it is so easy. No more guessing or squinting! Thanks #hannaaqua!!