Brilliance for Spas pH Decreaser. The Brilliance of Simplicity. There's nothing like finding the time to relax in your spa or hot tub and get away from the rest of the world. And now, you can use that renewed energy to take on the world, instead of your spa. The pH of water is measured of how acidic or basic it is. The pH scale runs from 0-14, with 7.0 considered pH neutral. Anything below 7 is acidic; above is basic. The ideal pH for Brilliance for Spas system is 7.2-7.8. Using Brilliance for Spas Test Strips, test your spa's pH regularly. It's simple to adjust. When the pH falls below 7.2 add Brilliance for Spas pH Decreaser. Always follow product label directions. To keep pH in balance, use Brilliance for Spas True. Make sure to read and follow label directions carefully when using this product.