This is my first post, and I can’t tell you how thankful I am for this community. We had some algae and started a slam. Usually, the slam clears everything up, but there are some stubborn black stains. I think it might be black algae and have been brushing it a few times a day with a steel brush while maintaining shock levels with liquid chlorine. Here’s a side-by-side picture taken on Day 2 (left) and Day 4/today (right). It looks like there has been some improvement, but I reaching out for feedback to make sure I am doing the right thing here. Do you think we are on track?