This year I ran into a problem which after 22 years of running the pool has never happened and I'm wondering if anyone else has seen this with their pool. After opening and balancing the water, I added some flocculent but this year I've developed a pasty layer of "something" on the vinyl liner that I can't get off by vacuuming. This is new to me and I was hoping there might be some wisdom out there that could help me clean up the liner. I'd be grateful for any advice, richardC/NH