Still havent had a problem. Mine is spot on. The supplied syringe works fine just fill it up to 1.0 and then plunge it down to .9 and your golden. I my case they Hanna is much much more accurate and i have tested using both salifert and hanna on a fresh mix saltwater batch of Aquavitro Salinity. The Hanna was 2 ppm off from the Lab test on the label. The Salifert was off this time by about 50 ppm, last time I tested they were within about 10 ppm. calcium test doesnt get much easier than the checkers.