I bought a New Hanna Magnesium test kit. Went twice through a Dry Run, then did my test. Then tested with the Red Sea Magnesium Kit. Hanna ran low. Decided to do another test, it came up, but still didn’t agree with the Red Sea. Which should I trust ?? Today I had a little more time to play with it. Out came my two 10 ml Graduated Cylinders. I found it was extremely hard to figure out where I should be with the Syringes, on the 4ml and 5ml measurements. I finally did put a a dot on each of the Syringes, for the liquid level. Also I measured 4ml into the vial, and put a line on it, ditto for the 5ml. I wrote to Hanna, with a suggestion. Will see what their response is.