I am changing out the liner in my newly acquired (with the house we bought last August) above-ground pool in two weeks. Today, as I was removing the old liner from the pool, I discovered a small hole in the pool wall about six inches up from the ground right below the top of the cove. It appears that there is rust on the inside wall, but no visible indications of any on the outside, other than the "BB" sized hole.

What to do?