Help with pool cover.......

My pool cover is a few years old and very worn. I have many leaves and algae all on top of the cover as well as water. I have been draining the cover but it seems that the pool water is seeping through because the water level on the cover just seems to stay the same. Also my pool water level has gone down 18 inches! How in the world am I going to get this mess off the cover so it won't go into the pool? I had a heck of a time last year getting rid of algae in the pool and I am dreading it this year too. Suggestions????