Amaze yourself and your next guest with a unique LED lighting system on the front glass panel of your new whirlpool tub. The Benefits of a PVC Piping System. The bathtub is designed so that water never remains in the lines of the whirlpool jets or the drain. This prevents bacteria, mold, & odor buildup that can be a problem in some jetted bathtub designs. Please note that this tub fills itself through the jets.