Help, Pool looks like lime koolaid

[waterbear]

without getting too technical let's just say that it is a more effective sanitizer at a pH of 7.2 than at a pH of 7.8. The chemistry behind it has to do with the equalibrium of hypochlorous acid (the stuff that chlorine forms when in water that sanitizes) and hypoclorite ions at lower and higher pH. But when you are dealing with algae sometimes a higher pH is better because it favors the production of monochloramine which is very effective against algae.
(I am going to stop now because it can get very technical very fast.....Just be aware that accurate pH measurements ARE necessary because the pH can affect many chemical reactions that take place in your pool!)