We just recently opened our pool and began testing chlorine levels with our ColorQ test kit purchased a few years ago, from your company. I have since noticed that the test drops DPD-1A and DPD-1B, purchased this year, appear to be defective. When testing the water the DPD 1-B drops turn a red color for only a short moment (3 to 4 sec) then they go nearly clear indicating a need to add chlorine. I know I have a more than adequate level of chlorinator in the water from a test strip test. I do not see any issues with the pH drops, the total alkalinity drops and calcium drops however I have nothing to compare them against as I already disposed of our remaining test drops from last year. Could these drops be bad also? Please let me know what the problem might be and when you can rectify it.

It would appear that the free chlorine level is so high, that it is destroying the test chemicals. Take a sample of pool water and mix it with 2 parts of tap water. Test the mixture. If you get a test reading, multiply it by 3. It won’t necessarily be an accurate answer, but could confirm the presence of a very high level.  Most testers only read chlorine, to 10 PPM.  You don’t need to add more chlorine, as you probably have far too much.  The reagents are not defective.  It is a very high level of chlorine, probably over 20 PPM, that is caused the quick fading.  Let me know what happens.