Water Hardness

Tap water may not be ideal pool water for the following reasons:

The quality and properties of tap water depend on the area that you live in. For example, water in Scotland is very "pure" due to the ground consisting of predominantely hard, granite rock. Hard rock does not readily dissolve on contact with rain water. So, the water remains relatively unaffected, only collectingminor material after it hits the ground.

This is given the term SOFT WATER and will have a slightly low pH value (acidic). If left untreated, this will lead to corrosion.

In Kent, with the chalky white rock, the rainwater picks up impurities such as Calcium Salts that increase the alkalinity of the water. This HARD WATER can be cludy and cause limescale formation.

Total Hardness

The Total Hardness (Calcium Hardness) of water is a measure of the amount of Calcium and Magnesium salts; such as carbonates, bicarbonates, sulphates and chlorides present. This is usually expressed in parts per million (PPM).

Water hardness is aided by water evaporation. If water evaporates, the dissolved minerals in the water remain behind thus, the concentration is increased.

Water hardness is important due to the water's hunger for Calcium. If there is a lack of Calcium (below 200PPM, the water will seek it out from the pools surrounding and fittings. This causes erosion problems.

An excess of Calcium, however, leads to scale formation (Calcium deposits).

The ideal Calcium hardness level is between 200 and 300 PPM.

Total Alkalinity

The total alkalinity of water is a measure of the amount of Carbonates, Hydroxides and Bicarbonates present.

This has an essential role in the control of pH in your pool. The higher the alkalinity, the more resistant the water is to changes in pH: the alkalinity "buffers" the water.

Common problems are limescale and cludy water.

When the total alkalinity drops too low, rapid changes in the pH can occur which could cause corrosion and harmful or disagreeable swimming conditions.

You can monito the total alkalinity with a test kit that can be supplied by Mister Sparkle Swimming Pools. The alkalinity should be maintained within a range of 80 to 120 PPM.

If alkalinity is too low, add some Sodium Bicarbonate. This increases the alkalinity without affecting the pH value. If the alkalinity is too high, add Sodium Bisulphate. All instructions are available on the labels of Mister Sparkle range of chemicals.