Water
Basics
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
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.
What
are hardness minerals?
Calcium, manganese
and magnesium are the most common.
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:
-
you use only 1/2
as much soap cleaning with soft water.
-
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.
-
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.
-
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.
-
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
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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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Improving your Drinking
Water
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.
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?
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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
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 Should 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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How Do I Interpret The Results of a Water Analysis?
At ESD we stand ready to help you interpret the results of a laboratory water analysis. As 30+ year professionals at water treatment and former experience as a laboratory director, we can help decipher the analysis results into the most sensible and cost-effective solution to your water treatment problem/s. Just click to drop us an email to let us know what you are dealing with. We'll work with you to determine the right technology and size/scale of water treatment device/s for your unique application.