How do you reduce foam in salt water hot tub?

The bubbles in a Jacuzzi (unless you are pouring detergent into it as a prank) is not the greatest thing to be getting into. The bubbles you are see is the dead skin particles from previous people who have been in the tub prior to cleaning. The bubbles will also contain hair from various parts of the body if you catch my meaning. The best way is to simply clean and drain your tub. More and more of your newer models of Jacuzzi (and off branded) are coming with an optional Ozonator. The Ozonator is (simply put) like the filter on a yard pool. Water is sucked into the Ozonator and is filtered removing all the bad stuff you have been swimming in. You might check to see if you can find an external Ozonator with someone like Spadepot or some other company online, if your model does not support it.