Quote Originally Posted by haze_1956
My question is not whether the calcium is there.

It was there 2 days after I added it, as shown by positve results on both test kits, (as per the instructions for each). Which leads me to believe the although these tests may be imprecise, they did show a Hardness presence, 600 ppm. I would conclude that if it was there then, and is still there now, the tests would again indicate it,

Now those same test procedures shows no presence. ( I added many more drops to see if color change would happen, however it didn't )

So my question is, where could the calcium have gone ?
Ther presence of a yellow color indicates some interference to the test...not a lack of calcium. Like I said before, there seems to be a problem with some unknown interference with these test kits. Not sure if it might be chlorine levels, pH, metal interferance, or what but these kits do not constistanly produce correct results.