I am having cloudy water problems with my Coyote Spa. My calcium hardness, TA, PH and bromine levels seem to be relatively easy to maintain but I seem to get cloudy water within a month of a dump and refill. Is is more than likely not enough shock ? I shock at the levels as suggested on the product but maybe I should increase the shock ? any suggestions ? also, last time I dumped the water there was a light white powdery film on the shell, came off easily with some vinegar and water but what would that have been, scale buildup ??? thanks