While I was enjoying our extended pool season, I swam around and ran my hands over the vertical walls of my IG vinyl pool. I felt several areas where the steel walls were rusting and if I pushed on the spots that were like little bubbles they would crunch and flatten out. A few places though, I found very tiny sharp protrusions among the rounder ones. I was afraid to push on them for fear they would puncture the liner. Is there anything preventative I can do? These would be tiny holes if they came through but they would certainly exacerbate the rusting problem then. I suppose it is inevitable that these 30 yr old walls would rust but I want to make them last as long as possible.