The Importance of Water Chemestry

Recently I have taken over several pools where the water chemistry has been neglected by the previous service companies. I have found damage to the pool surface, corrosion of equipment, and unhealthy swimming water. I know some companies promise to take care of your pool for a very cheap price, but please follow up behind them. Every month or so take a sample of your water to the local pool store for testing. Keep in mind the pH will rise between weekly services here in our area. All your other tests should stay in range.

Water chemistry is the most important factor when it comes to extending the life and appearance of any swimming pool.

Free Chlorine                       1 – 3 ppm

pH                                         7.2 – 7.8

Total Alkalinity                     80-120 ppm

Calcium Hardness               200-400 ppm

Stabilizer                              35-60ppm

PH Levels

PH is is measured on a scale of 0 to 14, with 7 being neutral. A pH below 7.0 means the water is acidic, and as the pH approaches 8.0, the water becomes (alkaline).

A correct pH level is needed in order for other chemicals to work  Chlorine is much less effective at higher pH levels; at a pH of 8.0, chlorine is only 22% effective.

It is also important to note that low and high levels can cause damage to a heater. Under the right circumstances, when the pH is below 7.0, the acidic water will shorten the life of the heater by eating away the metal components. A high pH can cause a scale buildup on metal parts.


Total Alkalinity

Alkalinity is the  alkaline materials dissolved in water. Keeping your alkalinity level in the 80-120 ppm range helps to stabilize the pH and prevent fluctuations. If the alkalinity is low, it can cause “pH bounce” — meaning the pH level fluctuates in and out of the correct range.

Calcium Hardness

Calcium Hardness is the amount of dissolved minerals within the water. A low hardness level can lead to corrosion of the pool surface, filter, heater,  etc.  A calcium hardness level that is too high can cause cloudy water and scaling .

Effects of Unbalanced Pool Water

·         Eye and skin irritation

·         Surface Staining and algae growth

·         Reduced efficiency of chlorine

·         Corrosion of pool component metals (pump seals, heaters, lights, etc.)

·         Cloudy water

·         Scale build up on pool surface and heater

·         Pitting and corrosion of plaster pools