Who's to say their's is not way off. I recently took my calcium reading with a SeaChem text kit (kit looks like a first aid kit, with the powders and the drops) My calcium level was 180 when i tested it. I had been dripping lime water for 2 weeks in a attempt to bring it up. No luck. Started dosing with Turbo Calcium and a week later tested with the SeaChem and it showed 350ish... Took said water sample to LFS and they stated probably over 1000 !!! My kit is 6 months old so who knows anymore. No idea how long they sit on the shelf before there bought. Any way, just thought id share my story.