So this web site here http://healthypools.org/freeteststrips/ is giving away free test strips and asking people to test pools all over the US and report back with the chlorine and pH levels. According to that site, "A properly maintained pool helps prevent recreational water illnesses, keeping swimmers healthy. The U.S. Centers for Disease Control and Prevention (CDC) recommends patrons use portable test strips to check pool water for adequate chlorine and proper pH."
pH values of 7,2, 7,4 or 7,8 are "acceptable", as are free chlorine levels between 1 and 3 ppm.
Cute charts currently indicate that 76% of the pools tested have unacceptable chlorine levels, and 80% have unacceptable pH.
I don't know where to start on that one, too many things to say, having patrons test pool water with test strips and posting the results "to compare" just sounds like a bad bad idea.