We just opened the pool for the first time Wedesday. There is a slight brown line at the water line on my white fiberglass steps in the shallow end and the swim out in the deep end. I got some kind of thick blue cleaner from the pool store but it is not doing much. I am afraid it is from our notorious red clay as our yard was full of it when we put it in last September. Is there anything else I can try? I like an immaculate pool and while the ring is not that noticable, I certainly know it is there. We have no ring on any other part of the liner, just the white steps and swim out. I have the TF-100 and kept my water very balanced last season, what time we had. It is balanced now with the exception of a little high TA of about 140. They added too much sodium bicarb at opening Wed.