After seeing some bad reviews online I still purchased a Hanna calcium checker a few months ago with a bit of trepidation. I will say that the test procedure was a little daunting at first and you only need .1ml of sample water, but it comes with a nice 100ul pipette that makes it pretty quick and easy to get .1ml every time. I believe that some earlier versions of the checker didn't include this tool. Once you get used running the test it becomes second nature and really isn't difficult to do.
I have been tweaking my alkalinity and calcium numbers a little and as such I have been testing daily The numbers I have been getting seem to be very accurate and predictable. I have been slowly raising my calcium and for the past 5 nights (after I increased my calcium dosing) the Hanna checker has shown an increase of exactly 6ppm every night.

I have been tweaking my alkalinity and calcium numbers a little and as such I have been testing daily The numbers I have been getting seem to be very accurate and predictable. I have been slowly raising my calcium and for the past 5 nights (after I increased my calcium dosing) the Hanna checker has shown an increase of exactly 6ppm every night.