When you mist your plants as often as I do, and you don’t use rain, or distilled water your plants will end up with water spots. I get rid of them with a product called Scrubbing Bubbles. I spray it on and wait for about a minute and then shower it off. The result is that the water spots are gone and you have a plant fit for a show. Only buy the product that is not Anti-bacteria. I have attached a photo to this post of the bottle that I use. I have also attached a photo from this weekend of Hoya megalaster, which I have sprayed with Scrubbing Bubbles many times before to no ill effects.