Monochloramine, Chlorine, CYA and pH

[smallpooldad]

Chem Geek and Waterbear,

Thank you for your replies.

I think I understand, and am glad I asked the question and challenged Waterbear's assumption, as I now know why this is the case. As stated I sat on the fence on this one and was open to having my mind changed, the explanation you give seems clearer and more concise here than in the other posts covering Monochloramine. I am therfore convinced that what Waterbear was trying to explain makes sense. What I am not sure of is how to best achieve results using this method.

The whole point of the previous log was to get rid of algae so which of the following methods would be preferable, and less expensive, assuming a pool which has a CyA of 40. and a pH of 7.5?

1. Get the chlorine to the recommended shock level based on Best Guess CYA chart not adding any acid to lower it to 7.2.

2. Lower the pH to 7.2, then shock based on Best Guess CYA chart .

3. Lower the pH to 7.2, then shock at FC 35-40.

3. Leave the pH at 7.5 then shock based on Best Guess CYA chart.

4. Raise the pH to 7.8 then shock to a based on Best Guess CYA chart.

5. Raise the pH to 7.8 then shock at FC 35-40.

6. Something entirely different.

7. It really does not matter which of the above methods one takes.

Looking forward to your reply(ies).

Aloha