When I had my liner replaced a couple of summers ago, I, too, had some rust. (My pool is above ground.) The guy sanded it off and sprayed it with something like rustoleum?? Not sure, but I *think* that is what it was. Al (Poconos) has seen my pool and has banged on the sides where the rust was and he thinks it is fine for awhile yet. I'll probably try and get a few more years out of it, but I'll certainly not wait til it HAS to be replaced before I do so. I don't need 13,000 gallons of water running towards my house!!

(Especially since I have 5 to 6 foundation repair guys and a backhoe in my backyard for the past week and maybe even for another week digging up my yard and repairing the cracked basement wall. NOT a fun thing to spend your money on and also not fun to have my yard be one huge mud pit! But, I will be getting a new deck out of this project )