I just got a new K-1766 kit, when testing my in-ground pool drops gob up and stay milky. I have tried adding way more drops then what should change the color, but nothing happens. I tried it on tap water and worked just fine. The pool is 14 years old, I have been using liquid chorine and trying to change it to salt system. I added 4 bags of salt before the test kit got here and a couple about 10 years ago.