The Pool Calculator
This is way too easy!
The Pool Calculator, http://www.poolcalculator.com, is web-based and takes out all of the guess work when adding chemicals to your pool. The Pool Calculator can figure out the amounts of chemicals to add, what FC levels are appropriate for your CYA level, what your Calcite Saturation Index (CSI) is, as well as help you estimate your pool volume.
To estimate the amount of any pool chemical to use, enter your pool volume in the orange size field near the top. Next, enter your current test results in the “Now” column and your desired levels in the “Goal” column, then hit tab, or press the Calculate button. This will do the computations for you and allow you to see what you need to do to get to your goal levels.
For every value except FC (Free Chlorine), approach your goal level gradually, instead of adding the full amount of a chemical all at one time. This is especially important with CH (Calcium Hardness) and CYA (Cyanuric Acid), which are easier to raise than to lower. In other words, be careful not to add too much. There will always be some estimation errors in your pool size, test values, and chemical measurements, which will result in levels slightly different from what The Pool Calculator calculates. The more time you spend understanding your pool, the easier this will get.
To estimate the number of gallons in your pool, look for the “Estimating Pool Volume” section towards the bottom of The Pool Calculator page. That calculation requires you to enter an average length, width, depth, and shape. If the width, length, or depth of your pool varies, you need to estimate the average number. If your shape is not listed, you need to either divide the pool up into sections that match one of the available shapes or select the closest available shape.
It is common for a pool to have more than one depth. If you have a shallow end and a deep end, you can measure each end and average the two numbers to get an approximate average depth. For irregularly shaped pools the same thing can be done for the width and length: measure in a couple of places and average the results. For “L” shaped pools, you can divide the pool into two rectangular sections, calculate the volume of each, and then total the two volumes.
The Pool Calculator can suggest FC (Free Chlorine) levels based on your current CYA (Cyanuric Acid) level. Enter your current CYA level in the “Now” column of the yellow CYA row and press tab or click on Calculate. The Pool Calculator will then estimate the appropriate FC levels in the blue “Suggested FC levels” section towards the bottom.
The “SWCG” level is appropriate for day to day use with a salt water chlorine generator. The “Normal” range is suitable for day to day use when using other sources of chlorine. Be sure to keep the pool’s FC level at or above the SWCG’s level, or lower end of the normal range, as appropriate. “Shock” level is for when CC is greater than 0.5 or you have algae. The higher “Mustard Algae Shock” level is sometimes required when fighting persistent mustard algae or overly aggressive blooms.
The Pool Calculator can also calculate your calcite saturation index (CSI). Enter all of your available test results and look in the green CSI row, towards the bottom, for your “Now” and “Goal” CSI numbers.
The Pool Calculator makes it easy, and that makes more time for you to relax poolside!