Hello All....I'm a newbie...purchased this house in Oct and still haven't swam in the pool..lol..anyway, everytime I vacuum to filter then I go to backwash then rinse; the next day the dirt is right back in the pool! I don't like vacuuming to waste because too much water goes out of the pool and we are now on a budget so to constantly have to add more water to the pool will become expensive. Is this normal? Could there be something wrong with the sand filter?