Hi. My cya level is zero if I am doing the test correctly. I’ve only had the tf100 test kit a couple days and both times I did it I could still see the black dot after all of the mixture was in the tube. A little hazy but still clearly there. 3 days ago the pool store said it was 40. We haven’t drained any water since then. Could I be doing it incorrectly? We are having trouble keeping chlorine and have been adding 121 ozs of 7.5% bleach every night. Pool is crystal clear. Chlorine only gets up to about 3 and is gone by the next night. Ph is staying pretty high between 7.8 and 8. if I add some liquid cyanuric acid will that fix it? The salt chlorination is set on 50% and is working but still can’t keep the chlorine level up.