I agree with waterbear...katw78, please take some time and read around the forum before you start posting advice. We have some tried and true methods for clearing up water problems that don't involve dumping other stuff in the water that may cause other problems later.

Also, I'm curious about your reasoning behind the relationship between algae, pH, and chlorine levels--while lower pH may or may not help your chlorine be more effective, I have absolutely NO knowledge of algae blooms creating pH problems.
Janet