![]() Question: Why do I have to raise my pH to 8.0 or higher before I use YELLOW OUT®? Answer: In order to interact most effectively with the chlorine, YELLOW OUT® needs a high pH environment. Since most pool owners keep their pool pH between 7.2 and 7.6, you will probably need to raise your pH to 8.0 to use YELLOW OUT® effectively. pH can be raised with soda ash or a pH increaser and it usually takes at least 3-4 hours. back |