Pool water testing

Test your swimming pool water and add chemicals

This is a quick reference guide to swimming pool water testing. For more detailed pool testing resources please visit Pool Water Testing.

Test Method Frequency Add this
Chlorine Test strips
DPD tablets/ drops
Daily testing advised
At least weekly
pH Test strips
Phenol red tablets/ drops
Daily testing advised
At least weekly
pH+, alkali
pH-, acid
Total alkalinity Test strips
Tablet count
Titration drops
Weekly is advised
At least monthly
Alk Up
pH-, acid
Hardness : Calcium Test strips
Weekly is advised
At least monthly
Calcium chloride
Calcium chelating agents
Conditioner Turbidity
Test strips
Weekly is advised
At least monthly
Cyanuric acid
Total Dissolved Solids Electronic - conductivity Weekly is advised
At least monthly

The Golden Rule for pool water testing is TEA :   Test   Evaluate   Act

Select a pool water test for more information:

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Chlorine    0.3 - 1.0 ppm
Test for free chlorine or free available chlorine - at least twice a week but preferably daily when swimming pool is in use.
Add chlorine (granules, tablets, liquid or saltwater generated) to maintain a level of 0.3 - 1.0 ppm Free Chlorine.

Test for combined chlorine (combined = total chlorine - free chlorine)
Shock pool with chlorine/ non-chlorine shock if combined chlorine reaches 0.3 ppm or pool environment "stinks of chlorine".

pH     7.0 - 7.6
Test the pH at least twice a week
Maintain the pH of the pool water at 7.2 - 7.4 ideally.

This pH range is the pH of our tears and will result in the kindest swimming experience for our eyes. It is also the pH range at which chlorine is ideally active - not too aggressive and not too slow.

Use pH increaser, pH up or sodium carbonate to increase pH.
Use pH down, pH reducer, dry acid or any high grade liquid acid to lower pH.

Total Alkalinity    80 - 120 ppm
Test Alkalinity daily or weekly until stabilized, then test less frequently if the value does not fluctuate much.
Maintain the TA at 80 - 120 ppm to ensure perfect water balance and a more stable pH.

Use pH reducer or acid to lower the total alkalinity.
Use alkalinity up or sodium bicarbonate to raise the TA level.

Calcium Hardness / Total Hardness    250 - 450 ppm
Weekly testing in problem areas is advised.
Maintain the hardness at 250 - 450 ppm to ensure good water balance

Increase the hardness of soft water with calcium chloride, calcium flake or calcium-up products.
Calcium hardness can be reduced with chelating agents, calcium out products or by using zeolite sand in your sand filter.

Conditioner / Cyanuric Acid    30 - 80 ppm
Test weekly for swimming pools using stabilized chlorine products such as dichlor, trichlor, tabs or sticks.
Test monthly for swimming pools using salt chlorine generators, cal hypo or liquid chlorine products (bleach, Clorox)

Add cyanuric acid or use a stabilized chlorine if the level is too low.
Reduce cyanuric acid by partially draining and refilling the pool.

Total Dissolved Solids    < 1,500 ppm
Test more frequently in problem areas or for problem pools.

If the fill water has a low TDS value, partially draining and refilling the swimming pool will lower the level.
Low TDS is not an issue for swimming pool water, though it may cause some electronic equipment, such as ionizers, to function poorly.

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