pH refers to the intensity of acid or alkaline materials in your water.

If pH is higher than 7.6, scale can form on surfaces and excess foam may occur.

If pH is lower than 7, metal parts will corrode, and bathers may experience irritation.

Adjust Total Alkalinity before adjusting the pH or Chlorine (alkaline substances buffer your water against sudden changes in the pH).




Chlorine is the most popular type of disinfectant. There are three different types of Chlorine presents in the water of the pool:

Free Chlorine is the chlorine, which is available to be combined with the contaminants.

Combined Chlorine (Chloramines) is formed when free chlorine reacts with the contaminants. It irritates the eyes, mucous membrane and cause the typical “Chlorine Odour”.

Total Chlorine is the sum of both Free (active) Chlorine and the combined (used up) chlorine.

Periodically you will need to add more chlorine to the pool to maintain the optimum level of disinfectant. The free chlorine residual in spas should be between 3 and 5 ppm, and between 1 and 3 ppm in pools.

When the total chlorine level is greater than the free chlorine level it will be necessary to shock the pool to oxidize all contaminants.




Total alkalinity measures the amount of alkaline buffers in your water. Alkaline substances buffer your water against sudden changes in the pH.

Adjust Total Alkalinity between 80 – 100 ppm before adjusting the pH and Chlorine.

Raising alkalinity with Sodium Bicarbonate and lowering with Dry Acid (Sodium Bisulfate). Both products are available in Watertech Ltd.





High calcium hardness results in scale formation on the pool surfaces as well as scaling in the pipes, plumbing and filter. High calcium levels will also cause sore eyes of swimmers.

If the calcium is a result of pool chemicals, draining some or all of the pool water will lower the calcium hardness level. Then refill the pool with soft water. If the cause is the fill water, hardness reducers are available in Watertech Ltd.

On the other hand, you can increase the calcium hardness level by adding calcium hypochlorite.




Cyanuric Acid, also called Stabilizer, makes chlorine more stable when exposed to the sun ultraviolet rays. A low cyanuric acid reading indicates that the chlorine will dissipate very quickly when exposed to sunlight.

The most common way to decrease cyanuric acid levels is to drain (or partially drain) and refill the pool with fresh water.


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