Re: Oily film in my hot tub - Possible Source ?
clean the filter, , run the air jets, if it foams, it body oil that cause the foam, a cap full of defoamer will break up the bubbles but only hides the fact that the water is "dirty" . google spa maintenance, spas can make you sick.
I once a month drain my spa, scrub down the tub and refill, easier than trying to sanitize and balance the water, its only a 1k gal or so of water.