We will be closing our pool soon. After talking to a few people who have a pool similar to us they make special winter covers that goes in the track. Talked to another pool company that sells same pool in another town that said yes you need the special one and usually comes with the pool. My pool company had me purchase a regular before knowing I need a special one. Now plays stupid and said they have never seen one. Sorry for long post.. trying to find out what everyone uses on their optimum pool for winter cover.