These filters are used for the "adsorption" of the following four unwanted elements most commonly found in drinking water:
• MTBE (Methyl-tertiary-butyl-ether)
PF-4 filters are also designed to "adsorb":
• DBCP (Dibromo-chloro-propane)
• THM's (trihalomethanes)
• Herbicides & Pesticides
• Heavy Metal ions
MTBE: PF-4 elements are manufactured to exceed ANSI/NSF Standard 53, which requires that MTBE be reduced by at least two thirds from an influent rate (water going in) of 15ppb to an effluent rate (water going out) of less than 5ppb (> 95% reduction*). LEAD: Tests have shown that when 2000 gallon of influent water at a concentration of lead of 150-200 ppb pass through 200 grams of media at a flow rate of 1gpm, the lead level was reduced to less than 1ppb (>99% reduction). FLUORIDE: Testing for fluoride was based on 20-30ppm of the ion in the influent aqueous solution at a flow rate of no more than 3 gpm per cubic foot of media. Results of < 1ppm of the fluoride ion in the effluent were typical for the media (>95% reduction). Under optimum conditions, effluent concentrations of less than 50 ppb were readily achieved (>99.75% reduction).
Under normal conditions it is recommended that PF-4 elements be replaced at six-month intervals (If water is heavily contaminated with MTBE, fluoride, lead or arsenic filters should be replaced in four-month intervals).