I can't give you advice about this as well as some of our people can but I will tell you that about 5 years ago when I replaced my liner, I had rust. Once the old liner was removed, you could see places where the wall was rusted. My installer used a wire brush of sorts to knock the rust off and then sprayed it with Rustoleum. Haven't had any problems since then, but I'm not gonna push my look. I plan to purchase a new pool next spring. Haven't yet decided if I'll get another AG or build an inground pool this time.

Not sure if that helps you any, but thought I'd at least share. Good luck.