i opened a green pool this year. After SLAM was finally able to remove the algae and have a blue pool. Now m vinyl cover has stains which look like algae at the bottom. We use well water in our pool and is high in iron content. I don't know whether these are organic stains, stains from the iron in the water or stain from the one bottle of BANISH copper algaecide I put into the green pool ( that was before I discovered this forum). How do I get to the bottom of these stains and remove them?