My pool professional wants to add an oxidizer, PH buffer, and a stain inhibitor to my pool before closing. From reading this forum, I know that I don't need these things since my pool is clear and balanced, so I told him that I would handle the chemicals myself this year. My water is already 60 degrees so I was planning on just closing at shock level, which is 20 ppm and skipping the optional polyquat. When I told him that I was planning on closing at 20 ppm and adding nothing else, he told me that it wasn't wise to close with that high of a chlorine level because it will bleach out and deteriorate my mesh cover. He also said that he didn't think the chlorine at this level will last that long in our climate since we often have mild winters with little snow or freezing weather. I can't afford to replace my cover anytime soon and I dont want to open up to a neon green pool so I wanted to see if my pool pro's arguments against closing at shock level were valid or not. If the chlorine could possibly bleach my cover or won't last very long in my climate, I will use polyquat instead but I definitely won't be adding the chemicals my pool pro suggested.