PoolMath

Discover the pool calculator behind the perfect pool, PoolMath. Dealing with pools has allowed TFP to become the original authors of the best calculator on the net.

To help you better understand the calculator and keep your water clean and clear, you should also view the following:

For a more modern experience, we have the PoolMath App. If you have any questions please join us on the forums where over 200,000 users will be happy to assist. Welcome to TFP!

	Now	Target		Units
Size			Mouse over a field for detail
FC	Goal: Not Setup		Add of % bleach. Jug size . or add by weight or by volume of . Note: Dichlor and trichlor add CYA and lower pH. Cal-hypo adds CH.

pH	Not Setup		Given TA of and Borate of : Add by weight or by volume of washing soda or soda ash or add by weight or by volume of borax. Add of muriatic acid or add by weight or by volume of dry acid. Note: pH calculations depend on TA and Borate. Results are approximate and can be off significantly for large pH changes. Changing your pH will also change your TA. Users should be very mindful of their CSI when their pH is at the top of bottom of the suggested ranges.

TA	Not Setup		Add by weight or by volume of baking soda. To lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH. Note: Adding baking soda will also raise your pH just a little.

CH	Not Setup		Add by weight or by volume of calcium chloride or add by weight or by volume of calcium chloride dihydrate. To lower CH you replace of the water with new water, with CH of . Note:Users should be very mindful of their CSI when their CH is at the top of bottom of the suggested ranges.

CYA	Not Setup		Add by weight or by volume of stabilizer or add of liquid stabilizer. To lower CYA you replace of the water with new water. Note: It can take solid stabilizer 24 to 48 hours to dissolve.

Salt			Add of salt. To lower Salt you replace of the water with new water.
Borate			Add by weight or by volume of and of 31.45% muriatic acid to compensate for the pH increase. To lower Borate you replace of the water with new water. Note: The pH should be tested and adjusted as needed after increasing the borate level.
Temp			Mouse over a field for detail
CSI			Calcite Saturation Index - requires pH, TA, CH, CYA, Temp, uses Borate, Salt Less than -0.6 is suggestive of problems for plaster, tile, stone, and pebble pools. Greater than 0.6 is suggestive of problems for all pools.
Suggested FC Levels			SWG Minimum: SWG Target: non-SWG Minimum: non-SWG Daily Target: to Shock: Mustard Algae Shock: Suggested target FC levels based on the CYA level in the Now column for outdoor pools. Note: Be careful if your CYA is really and truly zero! With CYA above 90 we recommend replacing water to get CYA down before you start the SLAM process.
Suggested Goal Levels			Use suggested goal levels from: Primary source of chlorine: Pool surface: Note: Suggested goals are simply a starting point. There are many situations that are not covered by these basic guidelines.

Notes
Unless you are SLAMing your pool, it is always best to add less than the full amount, wait a little while to allow the addition to mix thoroughly, and then retest to see where you are. Also, keep in mind that the volume of powders can vary from manufacturer to manufacturer.

Estimating pool volume
A wide by long by deep pool holds .
If the depth varies, use the average depth of the pool. A good approximation is the shallow end depth plus the deep end depth divided by two. Irregularly shaped pools can be approximated by estimating the average length and width and using rectangular.

Effects of adding chemicals
Adding of will
Note: pH calculations are not exact. These numbers are only suggestive of the relative magnitude of the pH change you can expect. Small changes, +-0.4, with pH between 7.2-7.8, TA around 80-120, and Borate near zero will be approximately correct. The further you go from those ranges the less these pH changes will correspond to reality.