Whole House Water Filtration Systems - Part 1 - Selective Filtration Vs Reverse Osmosis

Are you considering a whole house water filtrationWith all these 'bells and whistles', the RO systems
system for your home? They are, without aare notorious for maintenance problems and high
doubt, the best way to provide good, clean wateroperating costs.
everywhere in your house, with ease andLeaving the 'Rube Goldberg' world of filtration, let's
convenience. In this article, we will take a look atenter the world of selective, or multi-stage,
some newer technology in comparison with thefiltration.
old, discuss some pluses and minuses of the twoThese systems also use activated carbon but,
systems, see what to look for when shopping,here the carbon is first blended with a chemically
and where to find the best buys.charged filter resin and then extruded, or
Before we begin, here are two points aboutcompressed, into a solid block containing tiny,
whole house systems, one plus and one minus.submicron pores.
The plus...either of these systems will removeSolid carbon has a tremendous filtering capacity.
harmful chemicals from your water supply andScientists say a solid block of activated carbon,
are a good investment in your family's health.one foot square, has a surface adsorption area of
Scientists have proven 50 to 70 percent of thefive square miles!
toxic chemicals entering our bodies get there byThis leaves plenty of area for the activated
inhalation and absorption. Those of us on municipalcarbon, even in smaller sized blocks, to filter out
water systems, treated with chlorine, havechemical contaminants, while the submicron pores
homes with elevated levels of chloroform gas,clean up any remaining sediment and
from showering, washing dishes or clothes, andchlorine-resistant cysts, like Cryptosporidium and
flushing toilets, according to the EPA. Removing allGuardia.
sources of such gases is a very good thing to doWhat about the filter resin that covers the
for your family's health.surface of the adsorption area?
The minus...lead is very toxic, and the EPA hasAs water passes over the resin, positively
declared any level of lead in drinking watercharged heavy metal ions in the water, like lead
unacceptable. Whole house units filter the waterand mercury, are forced to break their bonds
when it enters our home and, as the waterwith water, and attach to the chemically charged
travels from the filter to your tap, it will likelyresin like little magnets. Lighter minerals, such as
encounter lead from the pipe's soldering, or thecalcium and potassium, are not affected.
pipe itself (copper pipe is 15% lead). Realize thatThere you have it, the water is cleaned, and it still
only a filter on the tap (point-of-use) will insure allcontains its nutritious minerals. Selective filtration
lead is removed.systems are quick, so there is no need for holding
Okay, first, the older technology, reversetanks. Nor is there any need for booster pumps,
osmosis.back washing, or electricity, and they operate
The reverse osmosis process forces water tovirtually maintenance free, without wasting water.
pass through a screen with very tiny pores,What should you look for when shopping for
removing anything larger than a molecule ofthese systems?
water. The process also removes all minerals, butWhen you are shopping, beware of companies
has problems removing chemicals, because theirthat claim "certified components" versus "certified
molecular size is smaller than water's. In order toproduct." You want the product certified, not just
clean up chemicals in the water, RO must be usedindividual components! Also, make sure the
in combination with a carbon filter.product is UL, or Underwriters Laboratories,
If the water pressure in the home is too low, acertified, or has a comparable industry rating.
booster pump may be needed to maintainWhich is the better buy?
adequate pressure in the system. Even withYou'll find reverse osmosis units are consistently
adequate pressure, several gallons of water, orhigher priced than selective filtration units, and
more, per filtered gallon, will not penetrate thetheir operating and maintenance costs are grossly
filter. This water is back flushed with the trappedhigher.
contaminants, and wasted.All together, this makes selective filtration
As you might expect, this process is very slow,systems a blessing for consumers... not only are
consequently, in order to have an adequate supplythey the best filter system, they are also the
of water, under pressure, a storage tank with acheapest!
diaphragm is needed.