I got a magnesium salifert test today and make out what they mean on step six. It says hold the syringe with the tip facing upward and read the postion of the upper end of the black syringe part. Each division corresponds to 0.01 ml. The magnesium concentration can be obtained from the table or by use of the following equation: ppm Mg = (1 - reading step 6) x 1500. Now when i face the tip upward do i start counting the lines from the black rubber to where the water is or from where the water is to the tip?