My Drop Checker arrived from H.K. with a shiny bottle of Blue Water, but zero instructions. So I'm assuming the Blue Water is premixed reference solution and not PH solution. It looks too light to be PH solution and there is too much to be PH solution. There is enough in the bottle for about two fillls of the little light bulb glass.

So far though the colour is staying blue (1 hr) and does not match any of the colurs on the enclosed PH chart (light green for 6). Any thoughts or experience with this checker.