I am looking to install a water filter system and I wanted to test the water for free and total chlorine.

I understand from the city water report that it uses chloramine and NO chlorine ([test report][1])and that chloramine content averages around 4 ppm in the water supply. I purchased one of these to test it out. http://www.bulkreefsupply.com/insta-test-free-total-chlorine-strips-lamotte.html

The above product can measure free and total chlorine ( 0, 0.5, 1, 3, 5, 10 ) PPMs. I was surprised to find out after using these test strips that city supply has 0 PPM for both free and total chlorine.

Questions
1. Any idea how I can test if these test strips are indeed working?
2. Anything wrong with the way I have tested?


  [1]: http://www.sandiego.gov/water/pdf/wq13.pdf