Have you ever turned on a whirlpool and seen a bunch of nasty black gunk shoot out of the jets? I've heard it's either mold or some kind of bacteria that feeds off dead skin cells. Personally, I don't care what the stuff is - it's gross no matter what. If the water in the circulation piping sits stagnant for a while, there's a good chance that this black gunk will start growing; it can take as little as a month for this to happen.

To prevent this black gunk from accumulating in your whirlpool, you're supposed to clean it at least monthly, depending upon the manufacturer. Pretty crazy, huh? Here's what a few of the larger manufacturers say:

My two cents: Maintaining a whirlpool tub is a lot of work. Not as much as a spa, but still... who would have thought? Oh, and to Jacuzzi for only giving instructions to clean with their exclusive cleaning product - boo.

If you're planning to sell your home and you have a whirlpool tub, take the time to clean the system out, especially if you never use it. If a bunch of black gunk comes out of the jets when the home inspector tests the system in front of the buyers, they're really going to be grossed out with your bathroom.

Reuben Saltzman, Structure Tech Home Inspections - Email - Home Inspector Minneapolis