Hi everyone. I would like to thank all of you in advance for any help offered. I have lived in this house for nearly 7 years and have cared for the pool but have never really been able to enjoy it. Until now! I finally have time to address some finer issues and details. I am in the process of trying to remove old stains and discoloration from my 20k, indoor IG plaster pool. I think it is going ok but I ran into something today and I thought the only place I might find wisdom on the subject would be in this forum. So thanks again. Looking forward to finally being able to swim in my pool like a normal human pool owner.