Check the listing for details. Jandy Water Balance Calculator. Condition: New. Listed at 4.99 USD. Brand new jandy water calculator wheel. you spend these based on your pH and salt readings etc. to get your calcium saturation index to prevent scaling in your pool. have purchased a couple new salt cells and each one comes with a wheel. I already have one so selling the rest. Hope these help you out! they're really a nice tool. The Jandy Water Balance Calculator is a tool designed specifically for maintaining optimal water balance in swimming pools and spas. As a product from Jandy, a reputable brand in the industry, this calculator provides users with a convenient way to determine the correct levels of pH and chlorine or bromine for their pool or spa. This ensures that water is kept clean and safe for swimmers, allowing for a more enjoyable and comfortable swimming experience.