Correct pH and Chlorine levels recommended by Swimming Pools Thailand

pH

The pH is a measure of the acidity of the water. The pH scale goes from 0 to 14, where pH 7 is neutral. If the pH is above 7, the water is basic; if it is below 7 the water is acid. The optimum pH for pool water is 7.4, since this is the same as the pH in human eyes and mucous membranes. A pH of 7.4 also gives good chlorine disinfection.

Low pH:

• aggressive water, that can damage tiles, stone, sandstone, cement, tile grout, tile adhesive
• iirritation in the eyes and on  the skin
• damage to the fibreglass pool  shell or vinyl liner

High pH:

• poor chlorine performance
• skin irritation
• limescale precipitation
• cloudy  wate

The recommended pH is from  7.2 –to 7.6. Maintain  at  7.2 for best  performance when using  a salt  water chlorinator
To lower the pH, use pH Minus; to raise it use pH Plus

Chlorine

T.C.C.A. 90% chlorine sold by  Swimming Pools Thailand  is trichlorisocyanuric acid. The brand we sell is the superior POOLCHLOR  The Powder and is fast  disolving, the crystals or granulaes disolve at  a moderate rete,  while the tablets are slow release and do not contain the non-reactive neutral fillers that  afre found in  tghe cheaper brands.
Unstabillised hlorine is known as calcium hypochlorite (fgranules)) and sodium hypochlorite (liquid).

When a pool is dosed with either organic or inorganic chlorine it is free chlorine that attacks bacteria and
contaminants. As the chlorine acts it is converted into combined chlorine. Combined chlorine (also known as
chloramines) is ineffective, smells of chlorine and may cause irritation of the eyes and mucous membranes. To reduce the combined chlorine, the pool is shock chlorinated with calcium hypochlorite. The high chlorine content that forms
temporarily on shock chlorination disappears quite quickly in an outdoor pool, but can also be lowered with chlorine reduction compounds. Chlorine is continuously consumed in the pool, and different factors determine the chlorine consumption, including bathing frequency, water temperature, sunlight and pool size. A test kit is used to measure the chlorine content. Most kits measure free chlorine, but to measure the combined chlorine you need to measure total chlorine. Total chlorine is the sum of free and combined chlorine.

If organic chlorine (weekly chlorination) is used, cyanuric acid accumulates in the pool. Where the cyanuric acid content is above 100 ppm (mg/l), chlorine blocking may occur, making the chlorine ineffective. Cyanuric acid can be removed by adding water from the mains supply.

Cyanuric acid is already included in most chlorine sold for swimming pools. CYA astabilisise the chlorine from being  urnt  off by  the sun before it  has done its work.
It is therefore advisable for outdoor pools to have a cyanuric acid level of 10-20 ppm (mg/l).