Hi all I'm new to the forum and would like to say hi and ask a question. We put our pool in last year fall and are getting ready to winterized it soon. Had a great year swimming and learning about pool upkeep. We had good success with the first few weeks of swimming and then went through an array of water issues. After some trial and error we found we didn't have enough stabilizer in the pool water is crystal clear now and all the test are right were this forum says they should be. But at some time over the summer we got some type of scum on our auto cover( underside) at first we thought it was the water but we found that after 30 min or so the scum was gone for the day, if we leave the cover open it doesn't come back and as soon as we close it then open it right back up there it is. I'm not sure how to get this cleared up. I have tried to use enzymes and leave the cover closed a couple of days but still have the same problem. I also shocked the pool with a Super chlorinate and granular to bump the chlorine up and left the cover closed for a couple of days no go. Thanks for any help you can provide.