EcoWater CHC Installation & Service Manual page 32

Terminology
pH: The pH is a measure of acidity or alkalinity of water. pH < 7 is acidic, pH > 7 is alkaline and pH of
7 is neutral. As pH increases, water becomes less corrosive but the scaling tendency of some insoluble
salts, such as calcium carbonate and calcium phosphate, increases. Each time you descend a whole
number (for example: from 7.0 to 6.0), the acidity of solution increases by a factor of 10. Thus, a pH of 6
is 1000 times more acidic than a pH of 9.
Range
Acid
Neutral
Alkaline
Alkalinity (Alk.): Alkalinity is a measurement of the buffering capability of water with the addition of
acid. With the addition a certain amount of acid, pH can lower dramatically for water with low alkalinity,
but pH only decreases slightly when its alkalinity is high. The main contributors of alkalinity are
carbonate ions, bicarbonate ions, hydroxide ions, and dissolved CO
-
bicarbonate (HCO ) is the dominant contribution to alkalinity. Alkalinity affects both corrosion and
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scaling tendencies.
Calcium Hardness (Ca): Calcium is one of the principle elements making up the earth's crust. Calcium
normally gets into water when rain water causes calcium carbonate to leach from limestone deposits in the
soil. It is the major contribution to water hardness. Calcium aids in the formation of soap curds during
cleaning and in some instances can form hard scale.
+
pH H
Concentration
0 1
1 0.1
2 0.01
3 0.001
4 0.0001
5 0.00001
6 0.000001
7 0.0000001
8 0.00000001
9 0.000000001
10 0.0000000001
11 0.0000000000
1
12 0.0000000000
01
13 0.0000000000
001
14 0.0000000000
001
The pH Scale
-
OH
Concentration
0.0000000000000
1
0.0000000000001 Battery acid
0.000000000001 Lemon juice
0.00000000001 Vinegar
0.0000000001 Orange juice
0.000000001 Coffee
0.00000001 Normal rain
0.0000001 Distilled water
0.000001 Milk
0.00001 Salt brine
0.0001 Baking soda
0.001 Milk of
0.01 Ammonia
0.1 Chlorine
1 Lye
Substance
Examples
water
magnesia
bleach
present in water. For most of waters,
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