Operating instructions

2-2
generally recommended (but only if the pumping rate is suffi cient to backwash the larger size).
If, however, the manganese concentration is low (0.1 ppm or less) and the pH is 6.5 or higher, a Chem-Free Iron Reduction fi lter containing
standard Chem-Free fi lter media will generally perform satisfactorily, although backwashing should be performed at more frequent inter-
vals. Under more severe conditions where the pH is very low and/or the manganese concentration is high, an acid neutralizer or chemical
feed pump injecting soda ash installed ahead of the fi lter will maintain the required 8.2 pH level longer than the Chem-Free Iron Reduction
fi lter will between replenishments with MpH Adder.
pH
The pH of water measures its acidity. Water with a pH of less than 7.0 is acidic, above 7.0 is alkaline, and a pH of 7.0 is neutral. The lower
the pH value the greater the acidity, and the higher the pH value the more alkaline. Acidic water (pH less than 7.0) is corrosive to pipes,
appliances, etc. A pH of 7.0 or higher facilitates iron reduction – which is why the Chem-Free Iron Reduction fi lter is designed to increase
the pH when it is less than 7.0.
The pH increasing component of the media is “sacrifi cial,” that is, it slowly dissolves during the process of increasing pH. The rate this
occurs is proportional to the degree of the pH increase and the water consumption rate (i.e., the greater the pH increase and water con-
sumption, the greater the sacrifi cial rate). Thus, when the pH is increased to 8.2 or more, as is necessary when manganese is present,
the sacrifi cial rate is even greater. Under the most severe conditions, the MpH Adder component of the media may have to be replenished
two to four times per year. On the other hand, if the raw water pH is 7.0 or above and no manganese is present, the sacrifi cial rate is very
slight (See NOTE, Sec. 1).
Tannins (Humic Acid)
Tannins (a humic acid), which may be present in some water supplies, are the result of various forms of decaying vegetation (the test for
tannins can be performed by your dealer). Tannins can cause problems in the operation of the Chem-Free Iron Reduction fi lter by forming
a sticky coating on the media, thus rendering it incapable of fi ltering the iron. Generally, with tannin concentrations of 0.5 ppm or less,
more frequent backwashing will prevent the sticky coating from forming. It does appear, however, that the level of tannin concentration
affects the operation of the Chem-Free Iron Reduction fi lter differently in different geographical areas (in some areas, the Chem-Free Iron
Reduction fi lter will perform satisfactorily when tannin concentration is considerably greater than 0.5 ppm). It is therefore recommended
that if the tannin concentration is 0.5 ppm or more, contact your dealer BEFORE installing the system.
Hydrogen Sulfi de (H
2
S)
Hydrogen sulfi de (often referred to as “sulfur”) is easily detectable by its objectionable “rotten egg” odor. Sulfur corrodes iron, brass, copper
and silver. While the Chem-Free Iron Reduction fi lter is not intended to be used as a sulfur fi lter, it is capable of reducing sulfur in concen-
trations of up to 2 or 3 ppm, and sometimes as high as 5 ppm. Whenever hydrogen sulfi de is present, backwashing must be performed at
more frequent intervals, and the pumping system MUST include a standard air-to-water pressure tank with an air-relief valve.