What Is a Micron Rating?
The average size of the openings between pieces of the filter media are represented in microns. For example, a 20-micron filter has larger openings than a 5-micron filter. Consequently, the 20-micron filter element will let larger particles pass through the filter than the 5-micron media would.
Bacteria range in size from 0.2 to 2 microns in width or diameter and from 1 to 10 microns in length for the nonspherical specie, so a 1-micron filter will remove most bacteria and cysts. If you are on municipal water, the water has already been treated with chlorine, chloramines and/or fluoride to remove bacteria, so chances are you do not have a bacteria problem, unless there is a problem with the water pipes between the water reclamation plant and your home. Although many customer purchase the 1-micron absolute for the kitchen because it can remove some pharmaceutical drugs, too,
If you are on well water and have a bacteria problem, installing a 1-micron absolute water filter at the point of use will remove most of the bacteria (99.9%), however, if your water has tested positive for bacteria, it is safer to install a chlorine injection water sanitizing tank to purify the water before it enters the house, followed by a whole-house filter to remove the chlorine.
As a general rule, the smaller micron rating for a filter is better, especially if you are on well water, but as with most everything, there is a trade-off. Flow capability usually drops off as the micron rating gets smaller, especially if the water has a lot of sediment, which well water often has. If the filter at the end of your kitchen sink spout needs to be cleaned frequently, it's a good bet that your water has a lot of sediment.
To overcome sediment-causing flow rate problems, low micron-rating filters must have larger elements to keep from sacrificing precious flow, like a sediment prefilter to remove larger particles that clog the 1-micron filter and reduce water flow. In a well water situation, it is common to see two or three sediment prefilters in the water flow, starting with the higher micron rating to remove the larger particulate, followed by lower micron rating filters. For example, first filter the water through a 20-micron sediment prefilter, then a 5-micron and finally through a 1-micron or a sub-micron filter. This process extends the life of all filters, including the carbon filters which do the work of removing disinfection chemicals and byproducts, heavy metals, herbicides, pesticides, THMs and other water pollutants.
Whole House models have the 5-micron because a 1-micron whole house filter would clog up and have to be replaced too frequently. Some whole house customers choose a 1 micron prefilter, which is significantly more affordable, but is replaced once every month or two.
Drinking WaterFilters - Facts and Myths
Water Filters Cartridge Life:
Neither we nor anyone else can tell you how long a filter cartridge will last in terms of time. We do not know how many people there are in your household nor do we know how much filtered water you and yours will use for drinking and food preparation. We express the life span in litres. A rule of thumb is to allow at least 1,500 litres per person per 6 months.
Tubes
At typical public water supply pressures the flow rate from the tap will be 3 to 4 litres a minute. 4 litres a minute is the fastest flow rate for any top quality carbon cartridge to be effective.
We see some vendors boast of using 3/8" tubing or more for faster flow rates but then advise you to turn the incoming supply down to 2 litres/minute for effective adsorption!
Activated Carbon
Basically, this is charcoal. The most used form in the UK is Bituminous (coal) Granular Activated Carbon or GAC.
Activated carbon is made by grinding bituminous coal, peat, or peanut or coconut shells and baking in controlled conditions to 540C in the absence of oxygen which bakes off the impurities.Then superheated steam at 870C activates the carbon and creates a massive network of pores that greatly increases the surface area of the carbon. This surface area is why carbon can absorb such large quantities of various compounds.
Coconut shell carbon is, by far, the superior carbon and adsorbs the widest spectrum of chemicals the most efficiently.
The newest and best activated carbon technology is Coconut Shell Activated Carbon Block. This is coconut shell GAC which has been further pulverised into smaller particles, then fused and then extruded. The result is all the top chemical adsorption qualities of coconut shell activated carbon but with finer particles giving a much larger surface area and much more activated carbon in the same volume as GAC; and with smaller micron ratings and a longer service life.
An additional benefit of carbon block is that the water is distributed evenly through out the media without 'Water Channeling'.
GAC is a loose media (like sand) and can suffer from 'Water Channeling" where the water keeps to the same waterways through the media. This results in some of the media not being used and leads to early depletion.
GAC is very effective for:
Volatile Organic Chemicals - pesticides, ie herbicides & insecticides, and solvents.
The Chlorine & Chloramine disinfectant dosed by your water supplier.
Trihalomethanes (carcinogenic chlorine disinfection byproducts) which arise when the chlorine kills organisms in the water.
Sediments and particulate matter to the stated micron rating - usually 20/25 micron.
GAC will also reduce other chemical contaminants but coconut shell activated carbon block is acknowledged as, by far, the superior media and method being effective for the widest spectrum of chemicals including carcinogenic:
PolyChlorinated Biphenyls or PCBs
New PCB contamination is vastly reduced if not eliminated as the regulations for the manufacturing industry ban their use. The problem remains because PCBs are hardy and take years to degrade. PCBs are not free in the water as such but are carried by particulate matter and organics. Removing the matter and organics takes out any PCBs that may be present.
Polycylcic Aromatic Hydrocarbons or PAHs
PAHs are formed naturally in the environment during thermal geological events (eg volcanoes) and natural fires. By far the biggest contributor of PAHs to the environment is the human race. PAHs are formed in all processes involving incomplete combustion of carbon-based fuels, and are therefore emitted during burning of common fuels, such as coal, oil, wood and gas. These settle on land and water and run off the land during wet weather.
Other chemicals
Pharmaceutical residues, endocrine disrupters and hormones (eg oestrogen)
A list would be almost endless and beyond the scope of a web page. Briefly and within context, chemicals can be split into 2 groups:
Hydrophilic & Hydrophobic.
Hydrophilic = water loving or soluble and usually attached to the water molecules.
Hydrophobic = water hating or insoluble and carried by the flow of the water.
Happily, common chemicals that may be found in public drinking water and are bad for us are mostly hydrophobic and are readily adsorbed by activated coconut shell carbon.
Myth: Activated Carbon is effective for Heavy Metals. Hardness (Calcium & Magnesium), Fluoride, Nitrates.
FACT: No it is not. AC will REDUCE these by mechanical filtration but so will a spun or wound Polypropylene1 micron sediment cartridge! The solutions for these need special media cartridges as previously described.
Myth: Activated Carbon is effective for pathogenic micro-organisms - bacteria and Cysts (oocysts); eg cryptosporidium and giardia
FACT: No it is not. AC will REDUCE these by mechanical filtration but so will a spun or wound Polypropylene1 micron sediment cartridge!
Effective filtration is only achieved with a sub-micron (less than 1 micron) cartridge and porous Ceramic is the material of choice with typical micron sizes ranging from 0.5 to 0.9.
However, the Health Protection Agency state "Campylobacter is the commonest reported bacterial cause of infectious intestinal disease in England and Wales. Two species account for the majority of infections: C. jejuni and C. coli. Illness is characterised by severe diarrhoea and abdominal pain....".
The size of Campylobacter is 0.45 micron and will get through a 0.5 micron filter. Public water supply utilities do not specifically test for Campylobacter.
Water filters work by having the contaminants 'stick' to the media.
Reverse Osmosis Purifiers use cross-flow filtration down to 0.005 micron and wash the contaminants to waste down your kitchen sink waste pipe (thus returning them to the environment).
MATRIKX® Pb1 0.5 – 1 micron activated carbon block water filters are excellent for any commercial or residential water purifier system where protecting growing children and pregnant women from LEAD and chlorine resistant CYSTS is important.
Will also greatly improve water clarity, and reduce chlorine, taste, odors, chlorine byproducts, organic chemicals, and sediments.
Matrikx® Pb1 Performance:
Key Uses:
Sediment Filters - Disposable