Water balance

Water balance

A "balanced" swimming pool means keeping the five basic pool water components (total alkalinity, pH, calcium hardness, stabilizer, and total dissolved solids) within their proper levels.

pH 

With low pH or high pH, water strips the body of its natural oils leaving skin dry and itchy, and hair brittle.

Basic water decreases the effect of your chlorine and causes cloudy water.

Acidic water corrodes everything from concrete to metal, in other words, from pumps and other mechanical systems to ladders. Good acid-base balance of the pool water will prolong the service life of swimming pool equipment, and on the contrary, it will cause loss of equipment.

With low pH, a vinyl liner can actually grow, creating unsightly wrinkles. If pH gets too high, a vinyl liner will age more rapidly and have to be replaced sooner.

The pH value of the most suitable swimming pool water should be in the range of 7.2 to 7.8 and the narrower range of 7.4 to 7.6 is better. It is essential to regularly check the swimming pool water quality.

Total alkalinity (or alkalinity, for short)

With low alkalinity, the pH of pool water fluctuates up and down and causes many problem. With high alkalinity, the pH of pool water is stabilized. If the stabilized value is out of the range from 7.2 to 7.8, it is hard to fix the problem.

The total alkanity of the pool water should be in the range of 80 to 140 mg/L.

Calcium hardness

If the level of calcium in pool the water is too high, it is easy to cause scale on the bottom or around the pool. When poor water quality corrodes the contact surface for a long time, spots or discoloration will remain on the bottom and wall of the pool.

In the other hand, for inground pools, too low calcium hardness will causes erosion of concrete. This also needs to be avoided.

It is recommended that you keep the calcium hardness in the swimming pool water in the range of 200-400 mg/L.

TDS (total dissolved solids)

TDS should be less than 2500 mg/L.  It’s hard to say what definite harm TDS does (because the kind of TDS is various and unknown before tests), but too high TDS level is always harmful.