Is My Whole House Filter Removing Too Much?

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gifty74

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I now filter through a whole house water filter (basic carbon filter) because I can keep the flow rate pretty high so it doesn't take forever to fill the HLT. I was just curious, what exactly do carbon filters remove? I just want to make sure I'm not removing too much out of my mid range water (like the calcium it needs, or other things that have an impact on alkalinity).
 
Effective Removal

Carbon filters are very effective at removing a number of deleterious chemicals. These include chlorine, benzene, radon, solvents trihalomethane compounds, volatile organic chemicals such as pesticides and herbicides and hundreds of other man-made chemicals that may come into contact with tap water as it proceeds through the system. In addition, filters remove bad tastes and odors from the water.
Ineffective Removal

Carbon filters are not particularly successful at removing dissolved inorganic contaminants and heavy metals such as minerals, salts, antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, copper, fluoride, mercury, nickel, nitrates, selenium, sulfate, thallium and other contaminants, which may require a reverse osmosis system or distiller instead. Carbon block filters can remove some large, dangerous microorganisms, such as giardia and cryptosporidium, that can cause a number of diseases and epidemics, but nothing less than the size of the carbon itself. Viruses are too small to be removed by carbon, as they usually range between 20 and 400 nanometers in size
 
If you flow through the filter at high rate, there is a good chance that nothing is removed from your water. This is especially true if your water supply is treated with chloramines. The flow rate through a carbon filter MUST be quite low to remove chlorine and MUST be ridiculously low to remove chloramines.

To effectively remove chlorine from water using a 10-inch undercounter filter, the flow rate needs to be about 1 gallon per minute. That drops to about 0.1 gallon per minute for chloramines removal. If the house filter is the larger 20-inch filter, then you can double those flow rates. That doesn't help much, does it?

In general, you may be better off employing metabisulfite treatment to remove chlorine or chloramines.
 
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