I am posting this in hopes it might help others. I started fighting a persistent yellow algae problem last year. I would think I had it under control only to have it return. This year I had a new liner installed and new water and even with that, shortly after opening the pool, I had yellow algae again. I started the SLAM process and completed it and then upped FC to 30 ppm. I had removed my plastic steps for the SLAM and scrubbed them and planned to put them back in during the 30 ppm process. As I was putting them back in the pool, a couple of the pieces came loose. When I picked them up I found that they had two small holes in them and were filled with water. When I emptied the water, huge pieces of algae came out with it. Since the only access to these pieces was through two small holes I realized there was no way I could totally get the algae removed but it did explain my continuing issues with the yellow algae. New steps have been ordered.