Thank you for the reply Watermom.

Let me explain a little more about the sides. When you rub the sides of the pool with your fingers it feels slimy and a white substance comes off and disperses in the water leaving a white cloud for a moment. Where you rubbed the slimy part it then feels like normal plaster. This has been going on for some time and there has never been any sign of algae. The weird cloudiness of the water only happens after the pool is cleaned and takes two full days to recover. Seems to me the water should be sparkling clear after cleaning. The filter pump is set to run for four hours everyday. Maybe thats not enough.