Orenda’s Pool Dosing Calculator


  1. At the top left, select whether the pool is residential or commercial
  2. At the top right, input gallons of the pool
  3. The left side is your current water chemistry. Test your water and adjust each item with the +/- buttons on the sides, or by tapping the number and typing manually.
  4. The right side is your desired water chemistry. Each number can be adjusted the same way as the left side.
  5. The goal is to adjust the right side to an LSI value as close to zero (0.00) as possible.
  6. Be sure your right side (desired water chemistry) is realistic, based on your current water chemistry. For example, dropping the pH while also trying to raise Alkalinity will be counter-productive.
  7. The Langelier Saturation Index (LSI) value adjusts automatically as you work. The color will be GREEN when the LSI is in the acceptable range. It will be RED when the water is out of the acceptable LSI range.
  8. When the right side has an LSI value that works for you, tap GET DOSAGE at the bottom.
  9. The results page will appear with two chlorine options for Calcium Hypochlorite and Liquid Bleach. Use one or the other, not both. If you use Trichlor or a different type of chlorine, this calculator does not include dosing for it, so adjust as necessary on your own.
  10. Below the standard chemicals are Orenda products and how to dose them. If you do not use Orenda products, these can be ignored. they will not impact your LSI score.

How to read the LSI

  • Perfectly balanced water is zero (0.00) LSI.
  • Positive LSI values above +0.30 means the water is over-saturated and likely to form scale. The higher the number, the more saturated the water.
  • Negative LSI values below -0.30 means the water is under-saturated and aggressive. It is likely to etch and corrode plaster surfaces and equipment. The lower the number, the less saturated the water, and the more corrosive it becomes.

LSI is calculated from six (6) factors:

  1. Water Temperature
  2. pH
  3. Calcium Hardness
  4. Carbonate Alkalinity
  5. Cyanuric Acid/Stabilizer
  6. Total Dissolved Solids (TDS)

Don’t worry, our pool dosing calculator does the math for you. Play around with each factor and watch how they affect the LSI score in real time.