EcoWater CHC, Installation & Service Manual

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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.
The pH Scale
Range pH H
+
Concentration
OH
-
Concentration
Substance
Examples
0 1 0.0000000000000
1
1 0.1 0.0000000000001 Battery acid
2 0.01 0.000000000001 Lemon juice
Acid 3 0.001 0.00000000001 Vinegar
4 0.0001 0.0000000001 Orange juice
5 0.00001 0.000000001 Coffee
6 0.000001 0.00000001 Normal rain
water
Neutral 7 0.0000001 0.0000001 Distilled water
8 0.00000001 0.000001 Milk
9 0.000000001 0.00001 Salt brine
10 0.0000000001 0.0001 Baking soda
Alkaline 11 0.0000000000
1 0.001 Milk of
magnesia
12 0.0000000000
01 0.01 Ammonia
13 0.0000000000
001 0.1 Chlorine
bleach
14 0.0000000000
001 1 Lye
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
2
present in water. For most of waters,
bicarbonate (HCO
3
-
) is the dominant contribution to alkalinity. Alkalinity affects both corrosion and
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.