Info from Clorox on using their bleach for pools

[chem geek]

I tested bleach and my injection solution again today and found the Clorox Ultra I bought from Sams is running about 7.2% by FAS-DPD test. What I can't figure is that a 1 to 3 (bleach to water) dilution is still testing at 2.4% solution for my injection pump. Does this compute??? (maybe it's this "new math" )

Well 2.4% is a lot closer than the 3.2% you reported earlier. When you say "1 to 3" do you mean 1 volume of bleach in 3 volumes of water or do you mean 1 volume of bleach into 3 total volumes (i.e. 2 volumes of water)? You are right that starting with 7.2% and truly diluting 1 part plus 3 parts water (a 25% dilution) should yield 1.8% and not the 2.4% you are getting. On the other hand, if you were doing 1 part into 3 total (so 1 chlorine and 2 water), then this would be a one-third diultion which should get 2.4% which is exactly what you got. So either there is something really screwy or your 1 to 3 wasn't 1 part bleach and 3 parts water, but was 1 part bleach into 3 total parts (2 parts water).

Perhaps if you explain how you did the 1 to 3 dilution this might clear things up.

Richard