I think it is algae now....

[waterbear]

Actually, higher pH is beneficial when trying to kill algae because it favors the production of monochloramine, which is very effective at killing algae.
This is how the Yellow Out stuff mentioned above works!.
Also, the effects of pH on chlorine's effectiveness are minimal once there is CYA in the water. If you had no CYA then the pH does become imporatant but with a stabilzied pool there is very little difference in the activity of the chlorine with low or high pH. (Note to Smallpooldad, check with Richard (Chemgeek) on this if you don't believe me! He will tell you exactly the same thing! The chart that you gave the link to above is only valid for an UNSTABILIZED pool.)