Need to add calcium

[haze_1956]

Used both an aqua chem and an hth test kit, same result on both, positve and negative.

Either way, it went from no reading. to a definite reading, back to no reading. over a 3 week period.

The calcium level did increase, then decrease as far as I can figure.

Thoughts?

[waterbear]

If I am not mistaken both these kits use a 2 reagent test. the indicator and titrant. The test in Taylor kits and Ben's uses a 3 reagent test; calcium buffer, indicator, and titrant; and does not have this problem....perhaps it is time for a better test kit? When you add the indicator it should turn pink if there is hardness present or blue if there is none. A yellow color indicates some interferance to the test. As a work around you can try adding more indicator drops until you get either the pinish or bluish color. I have done this and it has not affected the results when I have cross checked with a different test kit but I really don't know if this will alway be true. It might have some effect on the results.

[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 ?

[waterbear]

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.