I have some sticks at the bottom of the pool with leaves too. It is gross I have like either mold or algea up the sides of the wall just at the level the water sat all winter and yes I have I assume a layer of algea at the bottom. My pool is almost filled enough to turn on the new filter to see how it works and I have my fingers crossed on this one. I know my PH is above 8.2 and ALK is 90 neither one is good I have about 1ppm of chrlorine. I am very worried that I went from sand to cartridge and hope it is not more work when fighting algea. The pool guy talked me into it . any post will help and thanks