I hope you are feeling better You can try adding a sequestering agent first with your ph at 7 - no higher. This may lighten the stains. Your chlorine is too low, and I don't know how you are keeping chlorine in on a sunny day with a cya of 10- are you sure of these numbers? The metal out (sequestering agent) along with the low ph may lift the stains off. I wouldn't do the stain treatment again until you add the metal out and keep the pump running for a few days to see if the stain start to lighten up. If they don't - then the ascorbic acid treatment will be needed again. You always have to make sure you use a metal out (sequestering agent) when you do the stain treatment. If you don't the stains will come back as soon as you shock and have a ph over 7.5. If you have a lot of metals in your fill water, then you have to add sequestering agent on a regular basis. Feel free to ask any other questions you may have.