Janet has given you good advice. While you are converting, your high chlorine levels won't last for long. They will quickly drop as part of the conversion process. The more consistently you maintain the chlorine levels between 12-15, the faster your conversion will go. As many times a day as you can test and add enough bleach to get back to 12-15, do it. No such thing as doing it too often. Keep us posted how things are going!