Step 1. Check. You pH and Alkalinity using test strips and adjust the pH and alkalinity into the ok range.
Step 2. Soak your filters in filter cartridge cleaner, hose out and put back into the spa, that should fix the problem.
1. Make sure that whatever you wear while in your spa has not been washed in detergent or make sure you double rinse the garment. 2. Don't use oils in your spa. 3. Have a shower before entering the spa. 4. Keep your water in balance. 5. Keep your spa filters clean. 6. If your spa water is over 4 months old, use a pipe degreaser ,dump the water, clean and soak your filters in an approved filter cleaner and then refill your spa with fresh water.
NOTE:If all these suggestions don't work there is a product that will get rid of the foam and it is called anti foam. Follow the directions on the product label for best results.