Recently I was told by a pool company that the stain on my pool surface which is diamond brite is caused by the copper in algeacide. He told me the pool had to be drained and acid washed. The cost would be about 800. The stain is light in color. I live in florida so I thought I'd try ascorbic acid. Don t think I need to worry about algae since the water has cooled to 72 degrees. Maybe I'm wrong. Will the ascorbic acid treatment work on diamond brite? Any help is greatly appreciated.