I have Hanna calcium-HI758 and a alkalinity-HI772 checkers for sale. Both still have enough unexpired reagents for 4-5 more tests. Only reason that I'm selling is that I'm moving to the Salifert tests for calcium and alkalinity. Nothing wrong with them, and they both work great. You have to use distilled water for the calcium test, RO/DI water gives inconsistent results. The only issue is that the latches broke off the box on the calcium test. I would prefer local pickup in the Dallas area.