NPC LSI Calc 1.2

The NPC LSI Calc is a new, cutting-edge calculator designed for the precise determination of the Langelier Saturation Index (LSI) for swimming pools and spas. Developed by renowned pool and spa water chemistry expert and author, Robert W. Lowry, this calculator stands out as the sole LSI tool currently offering precise adjustments for cyanuric acid and borate.

The LSI serves as a crucial tool in determining whether pool or spa water is corrosive, balanced, or prone to scaling. Utilizing original mathematical equations which involve logarithms, square roots, and interpolated constants for computations without relying on outdated lookup tables or factors, the NPC LSI Calc ensures accuracy by utilizing actual water test results in its calculations.

Easy to navigate, users simply input the customer or pool name along with water test results for pH, Total Alkalinity (TA), Cyanuric Acid (CYA), Borate (B), Calcium Hardness (CH), Total Dissolved Solids (TDS), as well as the water temperature in degrees Fahrenheit. The LSI, complete with adjustments, is automatically computed and displayed, indicating water condition through a color-coded system that shifts from green to amber to red based on whether the water is categorized as Corrosive, Acceptable, Ideal, or Scaling.

Originally developed in 1936 predating the introduction of Cyanuric Acid (CYA) in 1960 and the recent popularity surge of borates as pH buffers, the LSI required modifications to account for these contemporary influences. Understanding the impact of CYA and borate on TA and subsequently on LSI calculations, adjustments were integrated into the NPC LSI Calc App to guarantee accuracy.

While it is advisable to aim for an LSI near 0.00, any value within the range of -0.30 to +0.50 falls within Acceptable or Ideal parameters. Positive values indicate a propensity for scale formation with readings exceeding +0.50 signaling scaling conditions that necessitate intervention. Conversely, negative values suggest a leaning towards corrosiveness with readings below -0.30 highlighting water conditions demanding corrective measures.

Resisting from proposing specific alterations to water conditions or chemical adjustments for achieving water equilibrium or desired LSI values, the NPC LSI Calc empowers service technicians, pool owners, or pool stores to make informed decisions tailored to their unique circumstances. Flexibility is key as users can input varying values for each condition to observe their impact on LSI.

Results can be conveniently stored and reviewed within the app with no constraints on the number of entries saved other than the capacity of your device's memory. Ease of data management is facilitated through simple deletion functionalities.

With its comprehensive features aimed at safeguarding pool surfaces, plumbing systems, and equipment while ensuring balanced water quality for clients, family members, or guests, the NPC LSI Calc emerges as a valuable asset in pool and spa maintenance.