Yes on the Hanna calcium test was very hard and inconsistent to draw 100 micro liters or .10 ml with the syringe I would get very large range test results. I get very consistent results with the pipettor test to test. Hanna even includes one now I think with the calcium checker. But I like using my own. I even built a little storage rack for them on my test station area of my work bench. I am very confident of the Hanna checkers and reading this thread has given me an idea on pre checking my Alk regeant as I usually buy 6 to 10 regents at a time.I actually have an adjustable 1-10ml pipettor. Bought it for taking water samples for tests, but hardly ever use it. It's sort of large and I am lazy to take it out of its own box. Those 10ml syringes are much smaller and I store them in Hanna's boxes and I tend to use these instead. But I never got the Calcium test, I was reading rather negative reviews on it and wasn't even considering buying it. I was thinking of choosing one larger box for all Hanna photometers and their stuff, and when I get at that I will probably make room for the pipettor to fit in there as wellas well. I have the Phosphate and Alkalinity so far, was planning on get the Nitrate HR and probably a salinity (conductivity) meter.
It is tempting to buy the Calcium meter too, although the reagents for it are the most expensive for some reason. Do you say that negative reports on this checker are mostly because of inaccurate doses of reagents added during the test?
I actually believe that the tests that normally are carried out by titration should be carried out just that way rather than by color change when a known amount of reagent is added. I would rather use an automatic titrator but that falls in a different price range, unless I DIY one... And, I was surprised that Hanna's alkalinity tester actually works quite well. Anyone knows what's in that reagent they are using? I wish I could make a DIY replacement for it.