Seems like an awful waste of reagents to test it that way. That would give a result of 100 ppm and would take 200 drops to verify. Knowing that 96oz of 6% gives me about 1.5ppm boost in my pool a half gallon sample would raise chlorine by 1.0. If I use a half gallon of the 15% it should give me 2.5. Even if the testing is not supremely accurate as long as it results in 2.0 its at least 12%, which is still a pretty decent deal at just over 16¢/oz of active chlorine. (Versus 13¢/oz if its 15%)