biz, chucks idea is good, btw - welcome to the forum, follow what you learn here to keep an easy to maintain pool! What I do for pink mold/ algae in my shower is to mix a 4:1 (water:6% bleach) in a 'garden/ plant sprayer' and spray it on and let it sit for a few minutes. When I rinse it off, the 'stuff' is gone and my shower sparkles. I think you could do the same thing with the cover; as you unroll it onto the pool, spray a 'shock' dose of 'bleachwater' on it and when it's fully unrolled, either dip it in the pool or rinse it with a hose. This isn't much different from Chuck's advice but allows you to use less bleach to do the job. Just an idea - Waste