Will my Doulton or British Berkefeld filter element remove all types of bacteria?

No, there are so many different species of bacteria of different shape, size and growth characteristics, which preclude the ceramic filter from being effective against all of them. The pathogenic bacteria that
FICL claim to be effective against have been qualified by test data from independent test laboratories or are extrapolated from test data, of similar microorganisms (please seek advice on permitted
extrapolated claims).
Also although the ceramic will filter all types of heterotrophic bacteria to some extent, it should be noted that any harmless bacteria of this type passing through the ceramic may multiply downstream of the filter. Since these heterotrophic bacteria are harmless, normally there are no problems and some heterotrophic bacteria are reported to be beneficial (see the section on Heterotrophic Bacteria pg 19).
However, if normal use of the filter is interrupted by holidays or vacations, growth of these bacteria may result in a ‘flat’ or ‘stale’ taste for a period of time when use of the filter resumes. This is especially true for the filter elements that contain activated carbon such as the Super Sterasyl (contains granular activated carbon), the Supercarb and Ultracarb (both contain an extruded activated carbon core). Any system containing activated carbon, which will reduce residual levels of free chlorine, will result in an increase in plate counts over a short period of time until a constant state of equilibrium is established. The UK Drinking Water Inspectorate water regulations call for the water to be regularly monitored for
consistency as used, therefore since an equilibrium point is reached in the filtered water, the filters comply with the regulations. The presence of this type heterotrophic bacteria does not constitute a health problem since the organisms present will be harmless and a suitable level of consistency would be established. Flushing the filter system for several minutes after any prolonged period of inactivity should eliminate the problem.

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