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Water Basics
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Water is generally
classified into two groups: Surface Water and Ground Water.
Surface water is just what the name implies; it is water found in
a river, lake or other surface impoundment. This water is usually
not very high in mineral content, and many times is called
"soft water" even though it usually is not. Surface
water is exposed to many different contaminants, such as animal
wastes, pesticides, insecticides, industrial wastes, algae and
many other organic materials. Even surface water found in a
pristine mountain stream possibly contains Giardia or Coliform
Bacteria from the feces of wild animals, and should be boiled or
disinfected by some means prior to drinking.
Ground Water is that which is trapped
beneath the ground. Rain that soaks into the ground, rivers that
disappear beneath the earth, melting snow are but a few of the
sources that recharge the supply of underground water. Because of
the many sources of recharge, ground water may contain any or all
of the contaminants found in surface water as well as the
dissolved minerals it picks up during it's long stay underground.
Waters that contains dissolved minerals, such as calcium and
magnesium above certain levels are considered "hard
water" Because water is considered a "solvent", ie,
over time it can break down the ionic bonds that hold most
substances together, it tends to dissolve and 'gather up' small
amounts of whatever it comes in contact with. For instance, in
areas of the world where rock such as limestone, gypsum,
fluorspar, magnetite, pyrite and magnesite are common, well water
is usually very high in calcium content, and therefore considered
"hard".
Due to the different characteristics
of these two types of water, it is important that you know the
source of your water -- Surface or Ground. Of the 326 million
cubic miles of water on earth, only about 3% of it is fresh water;
and 3/4 of that is frozen. Only 1/2 of 1% of all water is
underground; about 1/50th of 1% of all water is found in lakes and
streams. The average human is about 70% water. You can only
survive 5 or less days without water.
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Hard
Water
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What is
Hard Water ?
Hard water is the most common problem found in the average
home. Hard water is water that contains dissolved hardness
minerals above 1 GPG.
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What are hardness
minerals ?
Calcium, manganese and magnesium are the most common.
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How do you Measure
Hardness ?
Parts per million or grains per gallon are the most common.
One part per million (PPM) is just what it says: out of one
million units, one unit. Grains, or grains per gallon (GPG) is a
weight measurement taken from the Egyptians; one dry grain of
wheat, or about 1/7000 of a pound. It takes 17.1 PPM to equal 1
GPG.
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Why Should Hard
Water Concern Me ?
For many uses, it would not matter. For instance, to put
out fires, water your lawn, wash the mud off the streets or float
your boat, water would have to be pretty hard to cause a problem.
But for bathing, washing dishes and clothes, shaving, washing your
car and many other uses of water, hard water is not as efficient
or convenient as "soft water." For instance:
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you use only 1/2 as much soap
cleaning with soft water.
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because hard water and soap
combine to form "soap scum" that can't be rinsed
off, forming a 'bathtub ring' on all surfaces and drys leaving
unsightly spots on your dishes.
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when hard water is heated, the
hardness minerals are re-crystallized to form hardness scale.
This scale can plug your pipes and hot water heater, causing
premature failure, necessitating costly replacement.
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the soap scum remains on your skin
even after rinsing, clogging the pores of your skin and
coating every hair on your body. This crud can serve as a home
for bacteria, causing diaper rash, minor skin irritation and
skin that continually itches.
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for many industrial uses, the
hardness minerals interfere with the process, causing inferior
product.
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Who
Will Test My Water for Hardness ?
If you are connected to a municipal supply, call the water
Superintendent, or City Hall. They can either provide the answer,
or direct you to the proper individual. Remember the conversion
factor: it takes 17.1 PPM to equal 1 GPG. In other words, if your
water has 171 PPM calcium in it, divide 171 by 17.1 to get the
answer in grains. This example would be 10 grains, or GPG.
If you are on a private supply, you
could contact your county extension agent: collect a sample in an
approved container and send to the city or state health department
for testing: find a testing lab (try the yellow pages): call a
water conditioning company. By the way, if you are on a private
well, YOU, AND YOU ALONE are responsible for the safety of the
water you and your family drink. You should test your supply for
bacteria at least once per year and other contaminants at least
every three years -- more under certain conditions.
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My Water is Hard;
Now What ?
If your water tests over 3 GPG hard, you should
mechanically soften it. Softening water that is less than 3 GPG,
while it makes your shaving and bathing more comfortable, is
considered a luxury due to the fact that the cost is more than
your savings. Over 3 GPG, you will save enough to pay for the cost
and maintenance of a water conditioner.
As of this writing, the most
economical way for you to soften your household water is with an
ion exchange water softener. This unit uses sodium chloride (salt)
to recharge man made plastic like beads that exchange hardness
minerals for sodium. As the hard water passes through and around
the plastic like beads, the hardness minerals (ions) attach
themselves to the bead, dislodging the sodium ions. This process
is called "ion exchange". When the plastic bead, called
Resin, has no sodium ions left, it is exhausted, and can soften no
more water. The resin is recharged by flushing with salt water.
The sodium ions force the hardness ions off the resin beads; then
the excess sodium is rinsed away, and the resin is ready to start
the process all over again. This cycle can be repeated many, many
time before the resin loses it's ability to react to these forces.
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Which Water
Conditioning Company should I call?
As in any purchase, talk to your friends and neighbors --
who do they use? Are they happy with them? Check with the Better
Business Bureau for complaints. The BBB can't prevent shady
business, but they can and do keep a file of complaints filed by
people who have had dealings with them.
Ask at least two to come to your home
to look at your plumbing and then give you a quote on their
equipment. Have them explain all the features of the unit, as well
as the warranty.
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What Should I look
for in a Water Conditioner ?
Make sure the unit has enough resin to treat all the water
you and your family will use. As of this writing, the average
usage per day, per person (including children), for inside the
house is 87 gallons. You should also be shown two or three ways to
initiate recharging the unit.
The oldest way is by a timeclock, ie,
your water usage is calculated and the frequency of recharging
programmed into the timer. On the appointed day, at the appointed
hour, the unit recharges. If all went as calculated, ok. If you
were gone -- too bad -- you just wasted salt and water. If you had
extra company -- too bad -- you ran out of soft water. You must
pick a unit that will treat one days supply of water and still
have about 40% of the resin in the recharged state. This will
provide you with the most efficiency for salt and regeneration
water.
A second way to initiate recharge is
by electronic sensing. By electronically checking the resin, these
units can determine when the resin needs to be recharged -- this
is a great help when your water hardness changes, when you have
extra company or when you are gone for a few days. These 'sensor'
units can save you up to 42% of your salt and recharge water as
well as keep you in soft water when you have extra guests.
A third way to initiate recharge is
by using a meter. These units have a meter installed in the water
line and simply measure how many gallons of water you actually
used. The unit is set according to your water hardness, and will
recharge when the gallons used approach exhaustion of the resin
bed, saving you a high percentage of your recharge salt and water.
Many variations of these methods are
on the market. Some use computers to calculate in advance, when to
recharge the unit; some have two resin beds (tanks), and switch
back and forth between the two, keeping you in soft water all the
time, at the highest efficiency. These systems are most effective
in high-hardness waters, ie, over 10-12 GPG, and over 4 people in
the family. Low hardness water and smaller families do not require
the extra expense of these options.
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I Have a Water
Conditioner, Now my Water Feels "Slimy"
When the hardness minerals are removed, soap no longer
forms a soap curd, or "bathtub ring" on your skin,
plugging your pores, clinging to every strand of hair. You are now
truly clean. That slick, slimy feeling you feel is your natural
body oils -- without the soap scum. The old saying that you get
"squeaky clean" is a myth; that feeling was caused by
the soap scum on your skin. By the way, that soap scum provided an
excellent place for bacteria to hide and grow, causing numerous
minor skin ailments.
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Water
that Smells
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My
Water Stinks! What can I Do ?
First, you must learn a little about your nose: Once you
smell some things, your sense of smell is dulled for a short
while, and you can't make accurate judgments of smell. For
instance, if I blindfold you, let you smell gasoline, hand you a
piece of onion to eat and tell you it is an apple, you can't tell
it's not because your nose isn't working properly!! (Your sense of
taste isn't working either -- smell and taste are closely related
and affect each other!)
So, to correctly analyze your
problem, you need to become a detective. The best time to locate
the smell is after you have been away from home for a few hours --
this allows your nose to become sensitive to "that
smell" again. With your 'sensitized' nose, go to an outside
spigot -- one that the raw, untreated water flows from. Turn it
on, let it run a few minutes, then smell it. If it smells -- we
found it. If not, we must look further. (Many, many smells are not
in the raw water at all, they are introduced into the water inside
the house.) Go to a cold, treated water spigot inside the house,
turn it on and let it run a minute; then smell. If this water
smells, and the outside, untreated water didn't -- you must have a
device (cartridge filter, water softener, etc.) in the water line
that needs to be cleaned and sanitized.
If it is a cartridge, or 'string'
filter, replace the element and sanitize the housing. If you have
a water conditioner call the Company where you bought the unit for
advise on how to sanitize the unit. If you rent the unit, just
call! You can sanitize the unit by pouring Hydrogen Peroxide or
Chlorine Bleach in the brine well of the salt tank, and placing
the unit into regeneration. Check with the seller, or, if they are
no longer in business, any Professional Water Conditioning Dealer
for how much to put in your particular unit.
If the cold, treated water inside
didn't smell, turn on the hot water and let it run a few minutes
-- does it smell? If it does, chances are you have a sacrificial
anode inside your hot water heater that is "coming apart at
the seams" and throwing off a "rotten egg" odor.
This obnoxious smell will drive you right out of your shower! The
only solution is to remove the anode from the heater, voiding your
warranty, or replace it with a new one made with aluminum alloy.
This anode is placed in a (glass lined) hot water heater to seal
up any cracks in the glass lining and prevent corrosion of the
heater tank. You will find the anode on the top of the heater;
remove the tin cover and insulation -- look for what looks like a
pipe plug -- about 3/4 inch in size with a 1 1/16"fitting.
Turn off the heat source and the water; have someone hold the tank
to prevent it from turning, and unscrew the "plug". You
will find that the 'plug' has a 30 - 40 " long pipe (or
what's left of one) attached to it. Hopefully, most of the rod is
still attached -- just corroded. If so, replace the plug with a
real pipe plug and throw the anode away. If part of the rod has
corroded off, and fallen into the heater, you may have to try to
fish it out. Either way, before you plug the hole, pour about 2
pints of chlorine bleach into the heater first. This will kill the
smell left in the heater. If, after a week or so, the smell
returns, you must fish out the rod that is in the bottom of the
tank. Good Luck!
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OK, It's my Raw
Water That Smells -- Now What ?
First, you must determine what is causing the smell, and
how strong it is.
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Minor, musty
smell
If it is a minor, or low-level smell, you MIGHT be able to
solve it with a small, point-of-use carbon filter. You can place
these types of filters on the water line going to the cold water
where you draw you drinking water. Or, you might solve it with a
whole-house filter on your incoming water line to filter all of
the water inside your home.
Because carbon removes smells by ADsorbtion,
ie, the smell "sticks" or "adheres" to the
carbon particles, you must be careful not to exceed the
manufactures recommended flow -- some filters even have a flow
restriction built in them. If you run water through them too fast,
you will not remove the smells. Whenever you place a carbon filter
in your water line, you must be sure to replace the element and
sanitize the housing on a regular basis. Carbon filters remove
organics from water, and the bacteria found in water like to eat
organics -- the carbon filter is a nice, dark place, just full of
food for them to grow and reproduce in. Regular and routine
replacement will help prevent any buildup of bacteria in the
cartridge.
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Strong,
rotten-egg smell
Strong, rotten-egg odors in the raw water is usually the
result of the decomposition of decaying underground organic
deposits. As water is drawn to the surface, hydrogen sulfide gas
can be released to the atmosphere. In strong concentrations, this
gas is flammable and poisonous. It rapidly tarnishes silver,
turning it black. It is toxic to aquarium fish in sufficient
quantities. As little as 0.5 ppm hydrogen sulfide can be tasted in
your drinking water.
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Strong,
musty smell
If you are unlucky enough to have this problem, you should
look for a company that has local experience in dealing with this
problem. There are three basic ways to solve this problem for
homeowners.
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Filters
Installation of a whole house filter
loaded with a media that is specific for hydrogen sulfide
removal is successful many times. These types of filters must be
recharged with chlorine or potassium permanganate. The removal
capacities of these types of filters are usually fairly low, and
must be sized to contain enough media to prevent premature
exhaustion, and subsequent passage of the smell to service. It
is also typical that the amount of hydrogen sulfide can
fluctuate rapidly, causing great difficulty in sizing the unit.
In addition, potassium permanganate is extremely
"messy", and will leave stains that are very difficult
to remove.
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Feeders
Feeder systems consist of a small pump that injects small
amounts of chlorine (usually) into the incoming water. The water
must then be held for a short period of time to allow the
hydrogen sulfide to precipitate out of the water. This tank
should be designed in such a manner that the water that enters
it will mix thoroughly with the water in the tank, to assure
complete reaction. The water then should pass through a filter
to remove both the precipitated matter and the chlorine
remaining in the water. You should be aware, however, that
whenever you mix chlorine with organic materials (remember where
hydrogen sulfide come from!), the chances are very high that
trihalomethanes (possible cancer causing carginigns) will be
formed. Also, feeder maintenance is high, you should be prepared
to "play" with the unit frequently.
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Aeration
Aeration consists of breaking the incoming water into
small droplets (spray) into the air, drawing fresh air through
that spray, collecting the water into a storage tank,
repressurize the water, passing it through a particulate filter
to catch any particles that might be carried out of the storage
tank. The air drawn though the spray must be vented outside the
house -- remember, it is toxic and explosive. Although this
system necessitates another pump to repressurize your supply,
you are not adding any chemicals to your water, which makes it
attractive. This system is low maintenance and no chemicals to
purchase. Initial cost may be higher, however, and space
requirements may be greater.
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Water
that Stains
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I have
Red Stains in my Sinks and Other Fixtures -- Help!
Red stains are normally caused by iron in the water. You
must test to determine the amount and the type of iron you have.
Some types are: oxidized, soluble, colloidal, bacteria or
organic-bound. All are a problem! It only takes 0.3 ppm to stain
clothes, fixtures, etc.
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Oxidized
This type of iron is usually found in a surface water
supply. This is water that contains red particles when first drawn
from the tap. The easiest way to remove this type of iron is by a
fine mechanical filter. A cartridge type filter is usually not a
good solution, due to the rapid plugging of the element. Another
method or removal is by feeding a chemical into the water to cause
the little particles of iron to clump together, and then fall to
the bottom of a holding tank, where they can be flushed away.
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Soluable
Soluble iron is called "clear water" iron. After
being drawn form the well and contacting the air, the iron
oxidizes, or "rusts", forming reddish brown particles in
the water. Depending on the amount of iron in the water, you may
solve this problem with a water conditioner, or a combination of
softener and filter. You may use an iron filter that recharges
with chlorine or potassium permanganate, or feed chemicals to
oxidize the iron and then filter it with a mechanical filter. You
can sometimes hide the effects of soluble iron by adding chemicals
that, in effect, coat the iron in the water and prevent it from
reaching oxygen and oxidizing.
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Colloidal
Colloidal iron is very small particles of oxidized iron
suspended in the water. They are usually bound together with other
substances. They resist agglomeration, ie, the combining together
of like substances forming larger, heavier, more filterable ones,
due to the static electrical charge they carry. This iron looks
more like a color than particles when held up in a clear glass, as
they are so small. Treatment is usually one of two: Feed chlorine
to oxidize the organic away from the iron, thus allowing
agglomeration to occur, or, feeding polymers that attract the
static charge on the particles, forming larger clumps of matter
that is filterable.
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Bacterial
Iron bacteria are living organisms that feed on the iron
found in the water, pipes, fittings, etc. They build slime all
along the water flow path. Occasionally, the slimy growths break
free, causing extremely discolored water. If a large slug breaks
loose, it can pass through to the point of use, plugging fixtures.
These types of bacteria are becoming more common throughout the
United States. If you suspect bacteria iron, look for a reddish or
green slime buildup in your toilet flush tank. To confirm your
suspicions, gather a sample of this slime and take it to your
local health department, or water department for observation under
the microscope. This type of iron problem is very hard to
eliminate. You must kill the bacteria, usually by chlorination.
You must use high amounts of chlorine throughout your plumbing
system to kill all organisms. You may find it necessary to feed
chlorine continuously to prevent regrowth. A filter alone will not
solve this problem.
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Organic
bound
When iron combines with tannins and other organics,
complexes are formed that cannot be removed by ion exchange or
oxidizing filters. This iron may be mistaken for colloidal iron.
Test for tannins; if they are present, it is most likely combined
with the iron. Low level amounts of this pest can be removed by
use of a carbon filter, which absorbs the complex. You must
replace the carbon bed when it becomes saturated. Higher amounts
require feeding chlorine to oxidize the organics to break apart
from the iron and cause both to precipitate into a filterable
particle.
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I Have Blue or
Green Stains on my Fixtures -- Help!
You either have copper in your water supply, or you have
copper pipes and corrosive water. Test for copper in your water.
Test the pH, total dissolved solids content and the oxygen content
of your water.
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Copper
Copper can be removed by ion exchange, ie, a water
softener. The removal rate is about the same as it is for iron.
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Copper pipes
and corrosive water
If your pH is from 5 to 7, you may raise it by passing the
water through a sacrificial media. By sacrificing calcium
carbonate into the water, the corrosively will be reduced. If the
pH is below 5, you will need to feed chemicals into the water.
If the corrosively is caused by
excess oxygen, the hot water will be much more corrosive than the
cold. Treatment is by feeding polyphosphate or silicates to coat
and protect the plumbing, or to aeriate the water to release the
excess oxygen.
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Water
and Health / Disease
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What is
Cryptosporidiosis ?
Cryptosporidiosis is a disease caused by the parasite Cryptosporidium
parvum, which as late as 1976 was not known to cause
disease in humans. Until 1993, when over 400,000 people in
Milwaukee, Wisconsin, became ill with diarrhea after drinking
contaminated with the parasite, few people had heard of either
crytosporidiosis or the single-celled protozoon that causes it.
Since the Milwaukee outbreak, concern
over the safety of drinking water in the United States has
increased, and new attention has been focused on determining and
reducing the risk for cryptosporidiosis from community and
municipal water supplies.
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Improving
your Drinking Water
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Filters;
what can they do?
There are many types of filters available in the market
place today. I will try to group them by the method they use to
filter water. Almost everyone has seen the ads for the filter that
fits on the end of your kitchen sink or bathroom spigot. These
filters usually use two basic types of filtration: a filter 'pad'
catches the large (usually over 25 micron in size) particles or
'chunks' , and a small amount of carbon to adsorb organics and/or
chlorine. The main problem here is the flow rates at which they
are expected to work at. The consumer expects to turn the tap on
as normal and draw "filtered" water. To remove free
chlorine, for instance, standard engineering practices set the
maximum flow rate at 10 gallons per minute per square foot (144
square inches) of surface area of the carbon, *if* you are using a
standard 30" bed depth. To remove chloramines or organics,
the maximum flow rate is set at 5 gallons per minute per square
foot of surface area. If your spigot will provide a flow of 1.5
gallons per minute, what size filter do you need hanging on the
end of that spigot to insure that the chlorine and organics will
not be swept past through the filter, into your glass? If you
purchase this type of filter, make sure it has a way of limiting
the rate at which water passes through it.
Next comes the cartridge type filter.
Most common are the 10 1/2 or 20 inch long filters. This type
filter will usually have a removable housing, into which different
types of "elements" can be placed. A sediment filter
cartridge element can be manufactured to remove certain size
particles and larger. Most elements for home use will indicate 30
or 50 micron and larger removal. More expensive elements, usually
for industrial use, may indicate a particle size (in microns) and
add the words "Absolute" after it. No, it isn't Vodka,
it simply means that if it says 5 micron absolute, it means it!
Very few particles larger than 5 microns will pass through the
filter. The regular filter may say 25 microns, meaning that *most*
of the particles 25 microns and larger will be caught by the
filter. Remember, there filters actually get better, or more
effective, as they are used. The 'junk' in the water collects on
the surface of the filter and becomes a part of the filter as
well. As it builds up, progressively smaller and smaller particles
are trapped, and the flow rate through the filter slowly
diminishes. This slowing of the flow rate can be a source of
problems to water using appliances in your home. If you use such a
filter, regular changing of the filter element is very important.
Elements for these filters can also be carbon (block or granular,
or powdered), can be manufactured for use in hot water, can be
ceramic, pleated as well as many other configurations. Some
manufacturers are mixing a small amount of silver into the carbon
to help prevent any bacteria growth in them. This has yet to be a
proven methodology. In fact, make sure that such a filter doesn't
give off more silver than is allowed, if not rinsed thoroughly
prior to use, especially after a prolonged period of non-use.
Remember, all filters, carbon especially, trap organics that
bacteria feed on, and as the water sits without moving, they can
multiply rapidly. Always change the elements on a regular,
frequent basis.
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Selective
Resins
A relative newcomer to the market, some small filters now
contain resins that only remove specific things from the water,
such as Nitrates, Fluoride or Lead. Technology is rapidly changing
in this area; If you have a need for such a device, you should
ask for supporting test results from an independent testing lab to
verify that the unit will perform as advertised. Many states now
have legislation that requires such data be provided to you prior
to purchase.
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Deionization
Used mainly in labs, manufacturing processes, or for
serious aquarium owners, DI filters are actually more complex than
a filter. True filters, unlike the selective resin and DI units,
work on a mechanical basis: they just 'catch' the particles that
are too large to fit through the spaces between the filter media.
(Well, I fibbed a little; but who wants to know about the Van Der
Waals or Coulomb forces?) DI works by ion exchange, just like a
water softener. Just as a water softener exchanges sodium for
hardness minerals, a DI unit will have two types of resin in it:
Cation and Anion. Basically, the Cation resin (like in a water
softener) removes the ions with a positive charge, while the Anion
resin removes those ions with a negative charge. Instead of using
salt as a regenerant, acid and caustic are used. Some small DI
cartridges are sold as "throw-aways", others can be
returned for regeneration and reuse. These small units can treat
only small amounts of raw, city water. Usually, it is much more
economical to pretreat the water feeding a DI system with reverse
osmosis water.
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Distillation
One of the oldest methods for cleaning water is
distillation. Simply put, you boil water, catch the steam, and
condense it back into water. Theory is, the minerals stay behind
in the boiling chamber, and only *pure* water ends up in your
container. In the real world, most of those things do happen; but
if you do not perform preventative maintenance on your still, you
can get very poor results. Distillation will kill bacteria,
viruses, cysts as well as remove heavy metals, organics,
radionuclides, inorganics and particulates if properly maintained.
One thing you must watch out for is VOC's (volatile organic
chemicals). These chemicals have a lower boiling point than water
(like benzene), and can vaporize and mix with the steam, carrying
over into the product water. Some stills today have a volitle gas
vent -- a small hole at the top of the condensing coil that allows
the venting of such substances. Many distillers have a carbon
filter to "polish" the product water before use and to
remove any VOC's that may carry over. The energy used to treat a
gallon of water is usually about 3,000 watts, or about 25 cents
per gallon (average) in the US. This treatment method requires
that you 'plan ahead' and make and store water for use, which
makes it somewhat less appealing. The more elaborate units will
make and store water automatically, but raise the initial
investment and maintenance of the equipment.
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Reverse
Osmosis
This is a process that is often described as filtration,
but it is far more complex than that. We sometimes explain it as a
filter because it is much easier to visualize using those terms.
We should remember that osmosis is how we feed each cell in our
bodies: As our blood is carried into the smallest of capillaries
in our bodies, nutrients actually pass through the cell wall to
sustain it's life. Reverse osmosis is just the opposite: We take
water with "nutrients" (in this case, junk) in it, and
apply pressure to it against a certain type of membrane, and,
presto -- out comes "clean" water. Lets review the
basics: If you take a jar of water and place a semi-permeable
membrane (like a cell wall? or a piece of skin?) in it, dividing
the jar into two sections, then place water in both sides to an
equal level, nothing happens. But, if you place salt (or other
such substance) into one side of the jar, you will notice that,
after awhile, the water level in the salty side begins to rise
higher as the unsalted side lowers. This is osmotic pressure at
work: The two solutions will continue to try to reach the same
level of salt in each side by the unsalted water passing through
the membrane to dilute the salty water. This will continue until
the "head" pressure of the salt water overcomes the
osmotic pressure created by the differences in the two solutions.
On the other hand, researchers have discovered that if we take
that membrane and feed water with sufficient pressure to overcome
the osmotic pressure of the two waters, we can 'manufacture' clean
water on the side of the membrane that has no pressure. We
sometimes say we "filter" the water through the
membrane. Depending on the membrane design, and the material it
made from, the amount of TDS (total dissolved solids) reduction
will range from 80 to over 95 per cent. Different minerals have
different rejection rates, for instance, the removal rate for the
membrane I am looking at now is 99.5% for Barium and Radium
226/228; but only 85.9% for Fluoride and 94.0% for Mercury.
Removal rates are very dependant on feedwater pressures, and some
membranes are not tolerant to high or low pH. For home use, it is
important to make sure you get an RO *System*; ie, a sediment
prefilter, a carbon prefilter, membrane, storage tank and post
carbon filter. Some of these filters may be combined into one, ie,
the prefilter may be a particulate and carbon both. A lot of
comments have been made concerning the *wasting* of water by an
RO. True, the old style units with the early type membranes were
more prone to becoming plugged, or fouled by the "junk"
they removed from the water. To help keep this from happening, a
small amount of water was allowed to run across the membrane to
help carry away those impurities to drain. Early designs only
recovered 1 gallon of good water for every 4-8 gallons used to
keep the membrane clean. Even worse, when your storage tank was
full, water still ran to the drain because the early membranes
were made of a material that the little bugs in your water supply
(no, not pathogens, or dangerous to you in small numbers) loved to
eat! So to prevent that, we just let the water run so they
couldn't have time to stop and eat. :>) Now membranes are made
to not only recover a much higher percentage of the feedwater, but
the bugs don't eat them! Newer systems not only recover more, they
can have a shut off device that stops all water flow when the
storage tank is full. Actual recovery rate is dependant on several
factors, including the TDS, and just what the TDS is composed of,
in your feedwater. Temperature, pressure also have a big effect on
the amount of product water you can make in a given period.
Remember, all RO units are normally rated using a feedwater
temperature of 77 degrees F -- is your feed water temperature that
high?
What
is the best water for Coffee?
Well, that a good question! After visiting with many coffee
people, I have gathered the following as a basis for recommending
the "perfect water" for coffee.
1. All oxidants removed. (Chlorine or
other such sanitizers".)
2. All organics removed. (You know,
dead fish, tadpoles, THM's,
insecticides, pesticides, etc)
3. TDS (total dissolved solids) from
60 to 100 ppm
(parts per million)
4. Hardness of about 3-4 grains per
gallon. (51.3 to 68.4 ppm)
5. Low sodium water, ie, less than 10
mg/L.
6. pH depends on the Bean you are
using, plus the method
of extraction.
7. Iron, Manganese and copper gone,
or less than 0.02 ppm.
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What
is the best way to get this type of water?
There is no single answer for this question, however, if we
assume you are getting your water from a municipal supply, we
*assume* the Iron and Manganese problems are taken care of by the
city plant. (Some towns may not solve these problems -- you be the
judge!) Copper *may* come from the supply itself, or, if the water
is aggressive enough, it may actually be picked off the copper
plumbing in your house as it sits overnight in the pipes. (Lead
can also be leached out of the older "sweat" joints that
may have used solder that contained lead.) It is best to
"clear the pipes" the first thing in the morning before
using any water for ingestion. Simply run enough water to clear
your pipes of the 'overnight' standing water that *may* have
picked up the harmful metals from your pipes -- use it to water
your houseplants. If we use a good, properly sized carbon filter,
we will substantially reduce the organics and oxidants in the
water, as well as remove most of the particulates. However, we
still have TDS and Hardness to worry about. If we soften the
water, we do not reduce the TDS, we simply *exchange* the hardness
minerals for Sodium -- which we don't want for coffee! The best
answer (usually) is the reverse osmosis system. This *system*
usually has a particulate and carbon filter (organics, oxidants
and particulates are reduced); and a membrane (reduces the TDS by
about 90% -- including hardness, sodium and others as well); all
linked together in one flow path.
We can greatly improve the coffee by
using any one of the above mentioned methods, but if we combine
them, we get, for all practical purposes, the *best* water for
your coffee! Rule of thumb: With an RO System, whatever impurities
were in the water are typically reduced by 90% or more, leaving
only water behind, which is what we really wanted, anyway!
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How
much sodium does Ion-Exchange add to my water?
For every grain of hardness in your water, 7.5 mg of Sodium
will be *added* to each quart of water by the ion-exchange method.
If you have water that is 10 grains per gallon hard; you will add
75.0 mg of Sodium per quart of water softened by ion-exchange. To
put that in perspective, one 8-oz glass of milk contains 120 mg of
Sodium, one slice of white bread contains 114 mg of Sodium. You
must also remember that there is *probably* Sodium in the raw
water, too. If your city supply treats your water by a
"hardness reduction" treatment plant, you can be sure
that the Sodium level in your water has increased as a result --
how much? Call your plant operator and ask -- it is information
free to the public.
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Water
Testing Information
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When
Should I test ?
Several factors will influence when and how often you test
your water. Where do get your water from? Has that source changed?
Have you done any plumbing changes lately? Is there reason to
believe that your water is contaminated? Is there a sickness or
illness in your family affecting more than one person and over a
longer than normal time period?
If you receive your water from a
"Public Supply", ie, a municipal supply, or a supply
that provides water to more than 25 persons for 60 days per year
(some states are different -- check with YOUR local water
department), you can be fairly certain that the water supply is
checked on a regular basis. The frequency of the testing is based
on the number of people served, and may vary from more than once
per week to once per month, or even less. Under these conditions,
test when you move into a new residence to acquire a "base
line" of contaminant level, if any. Retest every three years,
unless you have reason to believe that something has changed that
could affect the quality of your water.
If you have a private well, you are
the only person who is responsible for the water your family
drinks and bathes in. I recommend testing by your local Health
Department every six months for Bacteria and Nitrate. These two
tests serve as indicators for other types of contaminations --
that is not to say forget the other tests; just that if you get a
"bad" test from them, you should also retest for the
other types of contaminants as well. Private wells should be
tested on a regular basis for Pesticides, Herbicides, Metals,
Organic and Inorganic chemicals and volatiles. Currently, no laws
govern the frequency of such testing -- that is why I say YOU are
the only person responsible for your family's water. I recommend
an initial test (for a base line), and then at least once per
year. Remember, one day after testing and finding "no
contaminants", your source could become contaminated.
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What
Could I Test For ?
Coliform bacteria are a group of microorganisms that are
normally found in the intestinal tract of humans and other warm
blooded animals, and in surface water. The presence of these
organisms in drinking water suggest contamination from a surface
or shallow subsurface source such as cesspool leakage, barnyard
runoff or other source. The presence of these bacteria indicate
that disease-causing (pathogenic) organisms may enter the drinking
water supply in the same manner if preventive action is not taken.
Drinking water should be free of coliforms.
Cysts and viruses are microbiological
contaminants, usually found in surface water supplies. Giardia
lamblia cysts can cause giardiasis, a gastrointestinal
disease. Another "bug" getting a lot of attention
lately, is cryptosporidium, single-cell parasite measuring
about 2 - 5 microns in diameter. Many surface water supplies
contain this pest, which also comes from the intestine of warm
blooded animals.
Nitrate in drinking water supplies
may reduce the oxygen carrying capacity of the blood (cyanosis) if
ingested in sufficient amounts by infants under 6 months of age.
This could cause a disease called "methemoglobinemia",
or "blue baby" syndrome. The EPA has established a
maximum contaminant level (MCL) for nitrate at 10 mg/l (ppm)
measured as N. Unlike coliform or other types of bacteria, boiling
the water will actually INCREASE the amount of nitrate remaining
in the water, increasing the danger to infants. If you have high
nitrate water, either treat it with an approved treatment
metholodgy or find another source: Boiling will only make it
worse!
Lead is now known
to leach from older sweat joints in copper pipe. As the water sits
in the pipes, small amounts of lead 'dissolve' into the water,
contaminating it. Lead is particularly harmful to small children
as they more rapidly absorb the toxic substance into their
systems. The EPA has estimated that more than 40 million U.S.
residents use water that contains more than the recommended
levels.
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