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Water Treatment Fundementals

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The need for safe, healthful water is critical to all human life. The search for ways to ensure a ready supply of high-quality water has been the life's work of some of our brightest scientists, and the amount of technical knowledge they have generated can fill volumes of text. Such a vast amount of knowledge is beyond the scope of this manual. Our need for knowledge of water quality issues is more practical, more job and customer oriented. We have therefore, made a serious effort to limit this manual to "purposeful information." We recognize that your time is valuable and limited. So, our goal is to give you the technical information that will help you feel more comfortable when solving your customers water problems


What is it about water that causes so much difficulty for those of us who bring it into people's home's, offices, hospitals, or factories?

We need to consider the nature of water. The primary answer is waters ability to dissolve some portion of nearly everything with which it comes in contact. No matter if the material is natural or man-made, water seems to always dissolve, and hold in solution, some part of what it passes through or is contained in. In fact, water is referred to as the "universal solvent." If the substances that water dissolves were all good for us, and if they did not damage our plumbing systems and personal possessions, there would be no need to study this manual.

Unfortunately, however, the substances that water dissolves can be unhealthy or even toxic. These substances can also ruin expensive plumbing fixtures and clothing. In addition, they can be offensive to our senses of taste, smell and aesthetic appearance.

Water can also "carry along" with it particles of sediment, dirt and rust. These are not dissolved in the water, simply carried with the flowing water, or held suspended in standing water. They can do damage just the same.


A final troublesome characteristic of water is that water is a welcome home (or medium) for all types of bacteria and micro-organisms. When allowed to go unchecked, this condition can cause problems ranging from minor intestinal irritation to serious illness or death.


If we think back to our school days, most of us can remember studying the "hydrological cycle." You remember, the process of how water vapor condenses in the atmosphere and falls to earth as precipitation. Once on the surface of the earth, most of the water evaporates back into the atmosphere, where it will again condense and fall back to earth as precipitation. About 30% of the precipitation, however, does not evaporate. Instead, it seeps into the ground or

runs off into streams, rivers, or lakes. As the water seeps in to the ground or as it flows over the surface, it dissolves minerals and other substances contained in the ground. Under the surface, the water tends to collect in porous portions called "aquifers." These aquifers are the source of our well water


Points To keep In Mind


Water as found in nature, will always have some substances dissolved in it.

It will always have the potential to have particles suspended in it.

It will always have the potential to be a suitable home to disease causing organisms.

This is true of "fresh" mountain streams, well water, and even municipally treated water systems. To achieve "pure water," or anything close to that goal, water must be filtered or treated in some way.

As you now can begin to see, the problem for us to solve will depend upon what the water has had contact with. These conditions can vary greatly, not only from one region of the country to another, but also within the same general location. Water drawn from wells in the same area may not be exactly the same. The quality of water from a municipality owned treatment facility will depend upon the age and condition of the equipment. Even though the water may be classified as safe to drink, the aesthetic quality may be less than desirable.


Fortunately, our knowledge of the nature of water has increased steadily over the years. The most frequently occurring problems have been studied very closely. We now know the symptoms, the cause of the symptoms, and how to cure the problem itself. Sometimes the symptoms are easy to read and easy to cure. Other

times, several problems exist in the water at the same time. Then it gets more complicated, and usually more-costly to correct.

Let’s examine these water problems as they will be reported to you by your customers ... the symptoms they see, taste, smell or fear. Along with the symptoms we will provide the cause of the condition, so you will be able to explain to our customer exactly what is going on with their water supply.




HARDNESS (Calcium, Ca) (Magnesium, Mg)

The term hardness refers to the quantity of dissolved calcium and magnesium in water. These minerals, which come primarily from limestone type rock formations, are found to some degree in almost all-natural waters. Calcium and magnesium cause problems for two principal reasons:

When the water is warmed, they precipitate out of solution and form a hard, rock-like scale. This scale accelerates corrosion, restricts flow, and reduces heat transfer in water heaters and boilers.

When they combine with soap, they react to form a curd, which interferes with cleaning, dries out skin, and leaves deposits on plumbing and clothes (bathtub ring; ring around the collar).


Hardness is measured in parts per million (or the equivalent mg/L) or in grains per gallon (gpg). Note, if the water analysis is given in ppm as CaCO3 then

1 gpg = 17.1 ppm. A common aspirin tablet weighs 5 grains). There is no established limit for the acceptable level of hardness in water, but it is generally considered to start to become problematic at around 3 gpg.

Levels of hardness are referred to as follows:

Soft water: 0-1 grains per gallon (gpg)

Slightly Hard Water: 3-3.5 gpg

Moderately Hard water 3.5-7 gpg

Hard Water 7-10.5 gpg

Very Hard Water over 10.5 gpg

Waters which naturally contain very little hardness can also be problematic because they may be corrosive in some applications (see acidity).

For some applications, sequestering agents (Siliphos) are good for hardness conditions under 15 gpg. The only practical method for hardness removal above 15 gpg in residential applications is through the cation exchange process employed by water softeners (also called conditioners).

Acidity (pH)

Water which contains excess acidity tends to act aggressively towards plumbing and fixtures, causing corrosion and staining (i.e.—blue green stains on fixtures from copper pipes). Relative acidity/alkalinity is measured on the pH scale, ranging from 0-14, where 7 is neutral, numbers lower than 7 are progressively more acidic, and numbers higher than seven are increasingly alkaline (basic). The pH value refers not to the quantity of acidity, but rather to the relative acidity/alkalinity of a particular sample.

Alkalinity acts as a buffer to de-activate the acidity, a process called neutralization. For example, limestone (calcium carbonate) is often applied to soil to offset the acidity which comes from acid rain and decaying organic material. The acceptable range for water is 6.5-8.5.

Acidity cannot be removed from water. However, it can be neutralized by raising the pH with alkalinity. This can be done by injecting a highly basic (alkaline) solution with a feed pump or by passing the water through a bed of processed limestone or similar mineral.

Iron (Fe)

The presence of Iron is a very common water quality problem, particularly in water from deep wells. Water containing even a significant quantity of iron may appear clear when drawn, but will rapidly turn red upon exposure to air. This process is called oxidation, and involves the conversion of ferrous (dissolved) iron, which is highly soluble, to ferric (precipitated) iron, which is largely insoluble. The ferric iron then causes red/brown staining on clothes, fixtures, etc.

Iron concentration is measured in ppm or mg/1 (milligrams per liter, where 1 ppm = 1 mg/1). Staining usually becomes a problem at concentration greater than 0.3 ppm. Removal is through ion exchange (water softener) or oxidation/filtration (APIR).

Manganese (Mn)

Manganese is a metal similar to iron which causes a grey/black stain. It can cause staining in concentrations as low as 0.05 ppm. Manganese is removed in a manner Similar to iron, although oxidation is more difficult, requiring a pH of at least 8.5.

Hydrogen Sulfide (H;S)

Hydrogen Sulfide is a gas which smells strongly like rotten eggs. It results from the decay of organic matter with organic sulfur and the presence of certain types et bacteria. Even very low concentrations are offensive as well as highly corrosive (silver tarnishes almost immediately upon contact with I-12S).

Because it is in the form of a gas, H2S cannot be collected in a sample bottle for laboratory analysis. Therefore its presence must be reported when a sample is submitted for a treatment recommendation. It can be removed by oxidation/filtration. aeration. or well sanitization.


Turbidity is a measure of suspended particles in water and can range from large particles which settle out of solution rapidly such as sand), to extremely fine sediment which may stay suspended in solution even after standing for hours. Treatment depends upon size, which is measured in microns.

Tastes and Odors

Most tastes and odors are caused by the presence of organic matter and chlorine. The vast majority of these can be removed with activated carbon



Organic Chemical Contaminants.

The presence of toxic chemicals at various concentrations has been widely documented in many water supplies. Detection can be difficult as these contaminants often have no taste or odor. Treatment depends on type and concentration. These chemicals may be industrial solvents or agricultural pesticides and herbicides. One of the most common is Trihalomethane (THM) which is formed when chlorine in the water reacts with natural organic matter.

Total Dissolved Solids (TSD)

TDS is the sum of the mineral salts in water and if too high can result in objectionable taste, cloudy ice, interference with the flavor of foods and beverages and scale lett behind in cookware. Generally speaking, the lower the TDS the more acceptable the drinking water. TDS of 1000 ppm or more is unacceptable for drinking water. Reverse Osmosis (RO) process

has proven itself as the most practical and cost effective method of correcting problems caused by high TDS.


Nitrates (NO3)

Nitrates are inorganic chemicals dissolved in some water supplies as a result of feedlot and agricultural activities. Nitrate levels over 45 mg/L as actual NO3 (or 10 mg/L as Nitrogen, N) can be a serious heath risk to infants and children.

Reverse Osmosis has proven itself as an effective method of reducing Nitrates to safe levels.


Heavy Metals.

Leads (pb) / Cadmium (Cd) / Mercury (Hg) / Arsenic (As) / Selenium (Se) / Chromium (Cr)

The so-called heavy metals are toxic elemental metals such as Lead, Cadmium, Mercury, and Arsenic that find their way into water supplies from natural and industrial sources as well as home plumbing. These metals, especially Lead, can seriously affect the mental and neurological development of infants and children. Reverse Osmosis (RO) is recognized as the most practical method of reducing Lead to insignificant levels in drinking water. Carbon Block technology that incorporates ceramic ion exchange media is also an effective method of reducing lead


Radium 226/228 (Ra)

Radium occurs in ground water due to the radioactive decay of Uranium in geologic formation. There is a health risk if the Radium level exceeds 20 pecocuries per liter (pCi/L). Cation exchange water softeners using proper regeneration procedures are effective in reducing Radium for POE applications. Reverse Osmosis systems are effective for reducing Radium for POU applications.




1. The only place to find naturally pure water is in a clear mountain stream

2. 1 gpg is equal to 17.1 mg/I.


Visible particles of dirt/rust/sand/clay and unclear water (turbidity); sediment in beverages; dripping faucets, leaky valves; cloudy water hydrogen sulfide gas in water
Rotten egg smell dissolved calcium and magnesium in water; often referred to as "hard water"
Scale formations (white spotting or coating) on glasses, valves, faucets, water heaters, or water heater elements; difficulty in lathering soap excessive chlorination
Chlorine taste to water; off tasting beverages high salt content; dissolved solids; salt water intrusion
Brackish taste decaying organic matter
Swampy, musty odors accidental spills or underground leaks of gasoline
Oil/ gasoline smell high concentrations of dissolved or oxidized iron and/or manganese in the water
Red/brown staining of bathroom fixtures, laundry, china, glassware and silverware; metallic taste; cloudy or discolored water acid type water, which measures below 6.8 using the pH scale
Blue/green deposits on sinks and tubs; corrosion or pitting of fixtures; metallic taste
tannins or lignins (decaying vegetation); oxidized iron (rust); excess air in water
Discolored water; yellowish, brown/red, or cloudy white (water clears after standing for several seconds) industrial discharges; sewage discharge; runoff of herbicides and pesticides; chemical spills getting into water supplies; aging or inadequate water treatment plants
Customer stress, anxiety or concern about health hazards such as bacteria or toxic chemicals in local water supply or well water industrial discharges; sewage discharge; runoff of herbicides and pesticides; chemical spills getting into water supplies; aging or inadequate water treatment plants

Most of the symptoms that your customers will bring to you are detectable by taste, smell or sight. Do not, however, overlook the symptoms that cannot be readily detected. The fear and concern caused by "unseen" impurities such as chemicals, metals, or micro-organisms is powerful. It is just as strong (if not stronger) a motivator as those more easily detected symptoms.


1)Red/brown staining of bathroom fixtures and laundry is caused by dissolved or oxidized_______    or_____    in the water.

2)__________staining is a sign of acidic type water, usually with a pH lower than 6.8.

3)Scale formation on valves, faucets, and hot water heaters is caused by and    ______in the water.

4)Rotten egg smell is caused by ________ gas in the water.

C. Measuring The “Ingredients” in water.

The world of water treatment has its own "language" that is used to express information. It's worth spending a little time learning this language so we will have an easier time understanding the extent of a particular water problem.

Dirt/Rust/Sediment Turbidity

Particulate matter suspended in water is referred to as turbidity and is measured in Nephelometric Turbidity Units (NTU). A range of .5-1.0 NTU is the required limit for potable water. Higher levels of turbidity should be corrected with filtration

Dirt/Rust/Sediment Micron

Another measurement, the micron, is useful for measuring the size of particulate matter. A micron is one millionth of a meter or about 1/25,000 of an inch. Particles smaller than 30-40 microns cannot be seen with the naked eye and a 5-micron particle is about the size of a single particle of flour or talcim powder.

Objectionable Color

Objectionable color in water is expressed in APHA units. Typically, color levels above 25 APHA are noticeable. At levels of 50-60 APHA the water typically requires treatment.

Objectionable Odor

Objectionable odor from water is measured by the Threshold Odor Number (TON). The TON is the dilution factor required before an odor becomes minimally perceptible.

pH Scale

The pH Scale measures the relative acidity/alkalinity of a particular water sample.
There are also several other contaminant measurement units with which you should be familiar. The first of these is pH, which measures the acidity or alkalinity of water due to dissolved substances.

Reaction Household lye
Extremely Alkaline Bleach
Extremely Alkaline Ammonia
Extremely Alkaline Milk of Magnesia
Strongly Alkaline Borax
Moderately Alkaline Baking
Slightly Alkaline Blood
Neutral Distilled water / Milk
Slightly Acid Corn
Moderately Acid Boric Acid /Orange Juice
Strongly Acid
Extremely Acid Vinegar / Lemon Juice
Excessively Acid Battery Acid
Very Excessively Acid

Dissolved substances in water are measured in milligrams per liter (mg/L) or the equivalent parts per million (ppm). If we dissolve 500 mg of table salt (NaCl) in one liter of water it is said that we have a 500 mgt (or 500 pprn) solution of Sodium


1) ---------------is a measure of the amount al dirt, rust, or sediment in water
2) --------------- Levels of pH below 7.0 are alkaline.
3) ---------------Tames and lignins are types of decaying vegetation
4) ---------------A 5micron particle is about the size of a grain of flour or talcum powder.


milligrams per liter (mg/L) = parts per million (ppm) 
micrograms per liter (ug/L = parts per billion (ppb)
1 ppm = 1000 ppb
1 mg =    gram (gm)
1 gram =    kilogram (kg)
1 kg = 2.2 pounds (lb)
1 grain per gallon (gpg) = 17.1 ppm as CaCO3
1 micron =    inch

3.785 liters = 1 gallon
1 gallon = 128 fluid ounces 1 gallon weighs 8.3 pounds
1 cubic foot holds 7.48 gallons 1 psi = 2.3 feet of water
1 foot water = .43 psi

Chemical Symbols
Calcium       Ca
Magnesium    Mg
Sodium      Na 
Carbonate     CO3
Sulfate                SO4
Chloride       CI
Bicarbonate   HCO3


The environmental Protection Agency (EPA) regulates U.S. drinking water supplies through the Safe Drinking Water Act (SDWA) passed in 1974. The EPA established standards for both health related (primary) and aesthetic (secondary) contaminants found in public water supplies. These standards are expressed in terms of maximum contaminant levels (MCL's) usually in units of Mg/L. The following charts outline the current standards

Chart 1

National Primary drinking Water Regulations.
Maximum Contaminant Levels.

Organic Contaminants 





2, 4, 5-TP(Silvex) 


Carbon Tetrachloride 


1, 2-Dichlorethane 

1, 1-Dichlorethylene 

1,1,1- Trichlorethane\Trichlorethylene 


Vinyl chloride 

Total Trihalomethanes 

(chloroform, Bromoform, Bromodichloromethane, Dibromochloromethane) 




Aldicarb Sulfone 

Aldicarb Sulfoxide 






m- Dichlorobenzene 

cis-1, 2- Dichlorobenzene 

1, 2- Dichlorobenzene 



Ethyl dibromide (EDB) 


Heptachlor epoxide 



Polychlorinated biphenyls (PCBs) 





Trihalomethanes (TTHMs) 




























.0002 (DBCP) 





















Gross alpha particle activity 

Bross beta particle activity 

Radium 226 and 228 (total) 




4 mrem/Yr 

20 pCi/L 

(1) In milligrams per Mar(mg/1) unless otherwise noted 

(2) No more than 5% of samples per month may be positive, or for systems collecting less than 40 2samples/month, no mote than one sample/month may be positive. 

(3) TT• Treatment Technique requirement established in lieu of MCls: 

effective beginning December 1990 

** Out of 7 m 1.44 only, 1 asbestos lave con be longer than 10 microns 

Chart 2

Secondary Maximum Contaminant Levels






Foaming agents 







Total Dissolved Solids (TDS) 


250 mg/l 

15 color units 


.5 mg/l 

.3 mg/l 

.05 mg/l 

3 threshold 

Odor number 


250 mg/l 

500 mg/l 

5 mg/l 

unwanted particles. The concept for water filtration is not different. A filter bed or fitter "media" is placed in the path of flowing water. As the water passes through the filter, unwanted particles are mechanically screened-out, and clean water flows out of the other end of the fitter.

Water Filtration and Treatment System.. The Cures!


Now that we have discussed the symptoms of water problems and their causes, it's time to move on to the cures. The water quality industry has focused its technology and equipment into two primary categories: Point of Entry (POE) and Point of Use (POU). POE technology filters or treats water at a point where it enters the building. From that point, the water flows through the normal plumbing system. POU technology, on the other hand, is placed specifically at a point where water exits the system, or where it is to be used. POU technology is primarily for drinking and cooking water.


The products and technology of the water quality industry are founded upon 10 basic processes, applied either individually or in combination with one another.



These 10 processes are:


2. ADSORPTION (Activated Carbon)


4. ION EXCHANGE (Water Softening)




8. MEMBRANE SEPERATION (Reverse Osmosis)

9. DEMINERALIZATION (Deionization)




Within these processes there are a variety of methods or techniques available. Let's look at each process and its current potential methods to-understand how each is used to cure water problems.




1. POE stands for ___________

2. POU stands for ___________

3. The products and technology of the water treatment industry are based upon _________basic processes applied either individually, or in combination with one another.


1.Particulate Filtration

As we are all aware, the purpose of a filter is to screen-out unwanted particles. The concept for water filtration is not different. A filter bed or fitter "media" is placed in the path of flowing water. As the water passes through the filter, unwanted particles are mechanically screened-out, and clean water flows out of the other end of the filter.

There are two basic types of filtration systems for removing particulate matter: backwashing filters, and replaceable cartridge filters. Under water conditions with excessive levels of dirt or particulates, a backwashing fitter may be used. The fitter "media" can be composed of a variety of materials, including sand, calcite, and manganese greensand, depending upon the specific water problem. These types of filters are "regenerated" periodically by having water backwashed through them (water flowing in the opposite direction).

However, under most circumstances, replaceable filter cartridges offer the most convenient and cost-effective means for treating dirt/rust/sand problems. Cartridge fitters are available for both point-of-entry and point-of-use systems. In order for these filters to work effectively they require replacement at intervals recommended by the manufacturer (e.g. at a given pressure drop) or based upon field experience

Replaceable cartridge filters are generally classified into four groups:
 • pleated paper filter           • spun polypropylene filter
   • string wound fifer             • bonded cellulose depth fitter
Graded density bonded cellulose fitters are constructed so that the spaces between the fibers become increasingly smaller toward the inside of the filter. With this design the larger particles are trapped on the outer layers and the smaller particles are trapped in the inner layers. Depth filters have proven to provide better particle removal due to their increased wall thickness. Or greatly improved variation of the bonded fiber depth filter is the "graded density" configuration.

The efficiency of a replacement fitter cartridge is based upon the size (in microns) of the particles that it will filter from the water. For instance, a filter which traps 5 microns particles will remove particles that are 5 microns or larger from the water.

Todays’ filters for POE use are designed in the form of cartridge units that tie into the cold-water line shortly after it enters the house. When the filter is spent, a replacement cartridge is easily inserted in the filter housing unit. The usable life span of a cartridge will vary according to specific water conditions and use levels. A good rule of thumb, for a properly sized fitter system, is to plan on replacing filters about twice a year.
As with many things in life, the most simple and direct solution to a problem is often the best solution. So it is with filters. They are the least expensive, most direct, and most effective solution to many of our most common water problems. Filters also

Bonded Cellulose Depth Filter

Flow path of AP110 H/C


In most cases, a water finer is considered to be ------------- in that at a certain point it will become clogged with removed particles and will need to be replaced.

Particulate filters can eliminate dirt, rust, and sediment.

What water problems can fitters cure? Actually, quite a few! First of all, given what we know about water conditions across the nation, it would be an outstanding idea for every home to have a POE fifer. Just as with an automobile when it needs to have its air, fuel, and oil filtered to insure quality and to protect the efficient operation, so too, we should filter our water to screen-out potential debris and contaminants. Specifically, fitters can eliminate dirt, rust, and sediment, even when they are as small as t micron.

Particulate fitters are a basic part of any sound strategy for treating water quality problems. Placing a particulate filter at the point-of-entry (POE) is a very effective method used to protect additional water treatment products installed in the household (i.e., Water Softeners, Reverse Osmosis and Drinking Water Systems). The fact that filters can be used in sequence or in combination with other processes to cure water problems with multiple causes makes them the versatile, first line of defense in our efforts to provide safe, aesthetically pleasing water to our customers.

2. Adsorption (Activated Carbon)

Adsorption is a process by which molecules of impurities adhere to the surface of activated carbon. The adherence is an electro-chemical attraction. Activated carbon is prepared from a variety of materials, such as, coal, wood, nut shells, peat, and petroleum. The carbon becomes "activated" by being heated to a high temperature (800 degrees Celsius) in the absence of oxygen. The result is the creation of millions of microscopic pores on the surface of the carbon. This vast amount of surface area provides a great opportunity for the adsorption process to take place. The activated carbon has a strong adsorptive attraction for other carbon based (organic) molecules, and is outstanding in firmly retaining heavier molecules such as aromatic compounds (those that we smell).

The adsorption process works like a magnet to hold impurities on the surface of I the activated carbon. This is unlike the action of a sponge which works on the 1 principle of absorption, in which a gas or liquid is sucked up into the center of a porous body and held there.

Activated carbon is also known for its outstanding ability to eliminate chlorine and its related taste and odor by chemically reducing it to an undetectable form (i.e. chlorides).

The effectiveness of an activated carbon filter is determined by 3 main factors:

1)The amount of time the water is in contact with the carbon

2)The contaminant level

3)The amount of carbon in each cartridge

Eventually, depending upon these factors and the amount of use, the activated carbon will become spent and will need to be replaced.

Activated carbon adsorption is often referred to as a titration process even though it is an electrochemical rather than a mechanical process. Cartridges containing activated carbon are commonly referred to as fitters, but it is important that you understand the difference.

There are several types of activated carbon fitter configurations.

1) Granular carbon—The most common form used for today's filters. Made from a variety of carbon-based materials such as coal, petroleum, nut shells and fruit pits.

2) Sliver impregnated carbon—also called Bacteriostatic or Oligodynamic carbon Some manufacturers coat the surface of carbon granules with silver compounds which are supposed to inhibit the growth of bacteria within the carbon bed. Because silver is considered a toxin, these fillers must be registered under the Federal Insecticide, Fungicide and Rodentaide Act. EPA sponsored testing of such filters have shown that they are "neither effective nor dependable in meeting their claims".

3) Compressed carbon or block carbon fitters—This is the newest configuration of basic carbon filters and offers some advantages. Very fine pulverized carbon is compressed and fused together with a bonding media. The intricate maze developed within the block insures contact with organic imputes. Some block carbon fitters are compressed so tightly that a pore structure can be developed that is capable of straining out virtually all pathogenic bacteria (v.4 microns) and Giardia (>2 microns).


Aqua-Pure actuated carbon "fitters" are manufactured with a depth bed of carbon. A depth bed of carbon is a large amount of activated carbon, through which water is directed. The goal is to have the water exposed to the activated carbon for as long as possible, and thus get the most benefit of the adsorption process. Aqua-Pure activated carbon fitters also incorporate graded density cellulose prefilters to protect the carbon bed from dirt, rust and sediment.

What water problems does the adsorption/chemical reduction process cure? Primarily

impurities and chlorine in water. Excess chlorine can also affect the taste of beverages made with water. Activated carbon can have some success in removing very slight amounts of "rotten egg" smell caused by the presence of hydrogen sulfide gas in the water, but it will not be effective with moderate or high levels. In such cases, the water may need to be heavily chlorinated first, to precipitate the hydrogen sulfide gas, and then treated with actuated carbon to remove the excessive chlorine taste and odor.

Activated carbon fitters are also effective for health related chemical removal in point of use (POU) systems. These chemicals include Synthetic Organic Chemicals used in industrial applications (e.g. solvents, paints, degreasers) and Disinfection By Products (DBP) such as Trihalomethanes (THM's). The Aqua-Pure Chemical Removal Filter differs from our Taste and Odor Filter in that it is designed to expose the water to greater amounts of activated carbon, for longer periods of time The Aqua-Pure Chemical Removal Filter allows a flow rate of 1/2 gallon per minute/1.9 liters per minute (1/6 that of the Taste and Odor Fitter). The water in the

filter is directed through an extra long flow path which maximizes the waters contact time in the carbon bed. The treated water is then directed to a third faucet installed on the sink, thereby ensuring that only drinking and cooking water is "filtered".

NOTE: Activated carbon filters should not be used on water that Is microbiologically unsafe without adequate disinfection before or after the unit. There Is a concern that the carbon can act as a haven for organisms to grow and multiply, although activated carbon has not been shown to foster the growth of pathogenic (disease causing) bacteria.



1) The process by which particles and molecular impurities adhere to the surface of activated carbon is called

2) Fitters can be used to eliminate dirt, rust, sediment, bad taste and odor, and chemicals from water, as well as to prevent scale build up.

True False

3) Activated carbon filters are especially good at removing bad taste and odors hum water.

True __False

3. Scale/Corrosion inhibition (Sequestering)


Water which contains high levels of hardness minerals can cause damaging “scale” build-up and corrosion of valuable plumbing fixtures and appliances. Sequestration is a process designed to inhibit this scale build-up and corrosion by dissolving an inhibitor agent (food grade additives) into the water. These food grade minerals consist of polyphosphate and sodium silicate compounds. Polyphosphate performs well under moderate hardness conditions. Sodium silicate differs from polyphosphate by providing good protection against mild corrosive conditions, CUNO utilizes Siliphos , a blend which has both compounds, thereby providing the best overall performance as an anti-scaling and anti-corrosion inhibitor, with a low dissolving rate.

Sequestration prevents calcium and magnesium, the causes of scale from precipitating out of the water and on to expensive fixtures and water heating elements. The Siliphos successfully ties up, or “sequesters” them, so they remain in the water.

Additionally, Siliphos acts to coat all the internal piping (and everywhere the water comes in contact) with a micro thin layer of glass-like material, called silicate. This film, which will mt build up on bet provides additional, direct protection from any scale build-up or corrosion.

It is important to note that sequestration does not "soften" water. Sequestration is a process that minimizes the damage and some of the problems associated with hard water, but it does not soften it and therefore will not improve its reaction with soap

How is water softening done? This process is based on the principle of chemical "for ion exchange" and if you remember the days of the study of science, the ions are atoms carrying an electrical charge, either positive or negative, and charged ions shipments positively called "positively charged ions," while those charged negative shipments called "negative ions charge "of the softening of the water process passes hard water through an intermediary for ion exchange (usually be made of reinforced plastic shaped beads rosary), and when the water passes through Alrating the positive ions charge of calcium and magnesium in the water exchange sites with positively charged ions ( Usually of sodium) and in the resin bed. In this process, two of the sodium ions from the resin bed are released for each calcium or magnesium ion is exchanged onto the resin bed.

**Siliphos is a trademark of Guilini Chemie GmbH.

4.Ion Exchange (Water Softening or Cation Exchange)


This term is used to describe the process of removing calcium and magnesium from water. Water containing more than 52 mg / L (or 3 atoms per gallon) of calcium and / or CaCo3 is considered "hard" water. Difficult water causes many problems for your customers. First of all, hard water interacts with detergents and soap to form a thin membrane that gathers around the wash basins and water basins and rests on the clothes, making them look dull and gray. Simply, hard water does not clean well either dishes, land or people, and perhaps the most expensive phenomenon of hard water is that this water can damage the pipe fittings especially where hot water is used.


What happens is that when water is heated, some calcium and dissolved magnesium in hard water are deposited outside and settle on the pipes and heating elements. This is the calcium and magnesium deposits called "peeling." Research has indicated that 1/8 " (Mm) of the flake coating on heating elements can increase energy bills up to 25%. In addition, the 3/8 inch (9mm) of the peeler on one of the heating devices can increase the bill of energy consumption on that device by 55% The flaking not only damages the plumbing but also makes it less energy efficient, and both cases It could have caused a direct loss of dollars to the customer.



1- Water that Contains above 3 gpg (or 52 milligrams per liter) of calcium or magnesium is considered to be hard water (True , False)

2- The build of scale in water heater elements is unsightly, but causes no real damage and does not interfere with normal operating efficiency (True , False )

3- Precipitated Calcium and magnesium is called:

a) rust b) contamination c) peeling

.4- Water softening works on the chemical process of:

a) insulation b) ion exchange c) distillation

5- The water softening process exchange________ for the cation of calcium and magnesium:

a) hydrogen ions b) chlorine ions c) charged sodium ions

As you can see. the water exiting the resin bed will be tree of "hardness" minerals, but the resin bed itself will. at some point. no longer have enough sodium ions to continue the process. When that point occurs. will depend upon the degree of hardness in the water, as well as the amount of water usage. Today's water softeners feature a method to “regenerate” the resin bed with a brine (salt water) solution. The brine solution soaks the resin bed for a period of time long enough to allow the sodium to replace the calcium and magnesium lodged in the resin bed. The calcium and magnesium are then washed away, leaving the resin bed regenerated and ready to be used again. The regeneration cycles are established at the time of installation and are based upon use demand, intake water quality (i.e. hardness, iron and manganese). and the maximum service flow rate needed by the household.


Those am as follows:

a. Service: hard minerals of calcium and magnesium are removed by cation exchange.

b. Backwash: the first stage of regeneration during which the resin bed is backwashed to tree it of turbidity and iron.

c. Brine Draw: the brine solution is drawn from the brine holding tank and it enters the resin bed.

d. Slow Rinse: the brine rinse is slowly forced through the resin bed. allowing the sodium to force the calcium and magnesium ions out of the resin bed.

e. Fast Rinse: raw water rushes through the resin bed washing away residual brine and calcium and magnesium ions.

f. Brine Tank Refill: water replenishes the brine tank to prepare for the next regeneration cycle.


The cation exchange resin in today's water softener is usually made at a synthetic material known as polystyrene resin. These resins have the highest rating for softening efficiency and they are not affected by normal variances of chlorine or pH levels.

Sodium chloride (salt) is most commonly used to create the brine solution that regenerates the ion exchange resin bed. Potassium chloride may be used as an alternative when sodium is a concern. When using potassium chloride, the salt setting on the control valve must be increased 50% to ensure complete regeneration of the resin bed.



Now that you have a fundamental understanding of how a water softener works. it is also important to understand how to size one property for its application. Unlike filters. which are generally sized to cover maximum flow requirements. water softeners are sized according to two factors, namely: 1) grains per gallon (gpg) of adjusted hardness, and 2) family size or water usage.

Most hardness test kits give the hardness in grains per gallon. If a water analysis is used and the calcium and magnesium or total hardness are given in ppm as CaCO3 (Calcium Carbonate) then:

grains per gallon (gpg) = (Calcium + Magnesium ) ppm / 17.1


grains per gallon (gpg) = Total hardness ppm / 17.1

If a water softener is to remove iron or manganese. it is necessary to convert them into a grains per gallon equivalent. The adjusted hardness may be determined by adding 3 times the amount of iron (4 times the manganese) in parts per million (ppm) to the hardness of the water in grains per gallon.


Example: water contains 19 gpg hardness. 2 ppm iron, and 1 ppm manganese

Adjusted hardness (gpg) = 19 gpg hardness

+ 3 x 2 ppm iron

+ 4 x 1 ppm manganese


29 gpg adjusted hardness

Once the adjusted hardness level is known, simply refer to the softener selection guide. Locate the box intersected by adjusted hardness and persons in family. Refer to the model series shown within the enclosed outline for the proper softener size.

To assist with rinsing, a mineral cleaner (A qua-Pure's "Iron-x"), should be added-with salt in the softener brine tank at a ratio of 1 oz. "Iron-x" for every 40 lbs. of salt.

What water problems can water softeners cure? Obviously, water softeners eliminate scale build up and the cleaning difficulties related to hard water They can also remove low levels of iron and manganese. There are, however, some limits for water softeners. Chief among these limits are the problems presented by moderate to high levels of iron and/or manganese in the water source. The problem is that just as with calcium and magnesium, iron and manganese will also exchange ions with the resin bed media. At low levels, the iron and manganese can be rinsed from the resin bed during backwashing. At high levels, iron and manganese become a problem in that they adhere to the inner portions of the resin bed, where they can become oxidized by dissolved oxygen in the water. When this happens, the iron and manganese precipitate onto the resin bed and will stubbornly resist removal by backwashing. Eventually, the ion exchange capacity of the bed is severely damaged and it cannot be regenerated. When water is tested and shows a high level of iron and/or manganese (more than 2 ppm), it is recommended that an Aqua-Pure Iron Removal System be installed ahead of the water softening unit.

Another caution relating to water softeners has to do with the levels of turbidity in the water. Large size particles and/or high turbidity can mechanically block the surface of the exchange resin bed, and so reduce its capacity to soften the water passing through it. In such cases, it is wise to install an Aqua-Pure Dirt/Rust fitter in the water line prior to the water softening unit.


Without getting too involved in detailed chemistry, we can describe "oxidation" as the process of increasing the positive valence on an element (by losing negative charged electrons). The opposite of oxidation is "reduction," in which the negative valence of an element is increased (by adding negatively charged electrons). Elements or compounds that can bring about an oxidation reaction are called "oxidizing agents." When these oxidizing agents are introduced to water, they read with the dissolved minerals and cause them to precipitate out of solution. The reaction also frees trapped gases from the water. Oxygen, chlorine, and potassium permanganate are the best known oxidizing agents in the water treatment industry

The most desirable oxidizing method involves exposing water to free oxygen either in the atmosphere or by injecting oxygen rich air into the water system. It is one of the oldest known methods of eliminating some common water problems. The oxygen in the air reacts with dissolved iron and manganese in the water, and causes them to precipitate out, so they can be removed by filtration. The process also frees the gas, hydrogen sulfide, allowing it to dissipate into the atmosphere. This helps reduce the taste and odor problem as a result.

The Aqua-Pure Iron Removal System utilizes an aspirator to inject small amounts of air (containing oxygen) into the water to bring about the oxidation. The Iron Removal System then provides a bed type fitter to trap the precipitated iron and manganese. Iron precipitates more readily with a pH of 7.2 or above and manganese with a pH of 8.2 or above. The Aqua-Pure Iron Removal System also contains a sacrificial pH increasing component. Under most conditions, it is necessary to install a standard air-to-water pressure tank equipped with an air release valve to vent released gases and gain increased contact time with the injected air. Water carrying oxidized or precipitated iron and manganese (now in particle form) passes to the Aqua-Pure Iron Removal System. The filter bed in the Iron Removal System is cleaned periodically by an automatic backwash cycle that takes 10 minutes and uses only 50-60 gallons (190-230 liters) of water.

A second means for creating an oxidation reaction Is with an Aqua-Pure Metering Pump that feeds chlorine into the water This results In both disinfection and oxidation

What problem does oxidation cure? High levels of iron, Hydrogen Sulfide, and manganese. These are sometimes very difficult to cure by filtration or water softening. Iron and manganese in solution can stubbornly mist filtration, and in water softeners, when ion exchange takes place, the Iron and manganese can oxidize and precipitate onto the Inner portion of the media bed, where they will be permanently lodged.

This reduces the efficiency of the ion exchanger, and shortens the life of the media bed. So, for significant levels of iron (up to 30 ppm) and manganese (up to 2.0 ppm), the oxidation/filtration process is recommended. You may want to note that it takes twice the oxidizing agent level to remove the same amount of manganese as It does to remove an equal amount of iron. Levels of Iron, however, are typically much more abundant than manganese in the make-up of source water.

6. Neutralization


This is the process of raising or lowering the pH level of water to bring It within the range of 6.5 to 8.5 on the pH scale.. the standard set by the SDWA. While high levels of pH (alkaline water) can con-ode certain metals, the predominant water problem in regards to pH level is acidic water (water with a low pH reading) The pH scale represents the relationship between hydrogen ions and hydroxyl Ions in water. A scale reading of 7.0 means these ions are found in equal concentration levels in the water. Water with higher concentrations of hydroxyl ions as compared to hydrogen ions moves the pH scale above 7.0 (up to a possible 14). Water with concentrations of hydrogen ions moves the pH scale downward (as low as 1). So, pH levels below 7.0 are acidic; pH levels of 7.0 are neutral; and pH levels above 7.0 are alkaline. We will concentrate on the neutralization process regarding acidic water, since it is the one most presented by our customers.


Acidic water can be caused by mine seepage or run-off, acid rain resulting from industrial as emissions, or from naturally occurring high levels of carbon dioxide in water without sufficient bicarbonate to offset it. Acidic water is usually "neutralized" in one of two ways. It is either treated through a media bed of limestone which reacts with the carbon dioxide to form bicarbonate, or through the use as a metering pump feeding a sufficient amount of soda ash (sodium carbonate) or potash (potassium carbonate) into the water to neutralize It.


CUNO offers a model for each method. The Aqua-Pure Acid Water Neutralizer installs on the cold water line and its design draws the water upwards through the fitter bed. This design eliminates "caking" of the media, and also eliminates the need for electrical power, or for backwashing the media. The neutralizing media is sacrificial and should be replenished approximately every year, depending upon the level of use and the degree of water acidity.


CUNO also otters a Metering Pump which is mounted adjacent to the Aqua-Pure Solution Tank (15 gaIJ56.8 kt,) and is powered by a gear driven electric motor which is weed to the water supply pump. That way, the pump dispenses the neutralizing soda ash (or potash) solution only when the water is running, and it provides precise pH adjustment as the water is used.


1- The process of raising or lowering the pH level of water is called_______.

a) Oxidation b) Adsorption c) Neutralization

2- To raise the pH level of water, __________ is usually added.

a) soda ash b) chlorine c) carbolic acid


3- In water treatment systems, neutralization can be accomplished with a limestone mineral bed or a(n) __________ .

a) ion exchangerb) chemical motoring pump c) sequestration filter


4- Oxidation/filtration is the most effective treatment for the problems caused by high levels of ________ in water,

a) iron and manganese b) calcium and magnesium c) bacteria and hazardous chemical


5- It takes ______ the amount of an oxidizing agent to precipitate manganese as it does to precipitate the same amount of iron.

a) the same b) twice the c) 5 times the


What are the differences between the two products. Well, there are some differences that might be important to our customer. The Aqua-Pure Acid Water Neutralizer is dependent upon contact time, raw water pH level, and hardness level. The longer the water sits in the limestone bed, the greater the increase in the neutralization of the water. For instance, water that has a pH of 6.0 may sit in the limestone bed overnight, and by morning, it may have risen to 9.0. If the water is run continuously, however, the contact time with the limestone bed will be reduced, and pH may rise to only 7.0. The lower the mineral content, or hardness level, the more readily the pH will adjust. The Aqua-Pure Metering Pump, on the other hand, will offer precise pH adjustment at a wider range of use levels.

Each of these products have advantages over the other. The Aqua-Pure Acid Water Neutralizer may be less precise than the Metering Pump, but it requires less ongoing monitoring and maintenance (on average, once a year). The Aqua-Pure Metering Pump, conversely, achieves precise neutralization, but the trade-off is that additional chemicals must be added to the system at intervals of approximately every 4 weeks.


What problems will neutralization cure?

Both neutralizing methods will eliminate the results of acidic water. Specifically, they will prevent blue/green staining, and the pitting and corrosion of copper pipes. In addition, these methods prevent lead contained in joint solder from releasing into the water as a result of leaching from contact with acidic water. Acidic water can cause serious problems with corrosion of plumbing systems and hazardous drinking water problems. For this reason, acid water should never be overlooked as a minor problem, but rather should be treated accordingly.



1- The most frequently employed method of disinfection is

a) Adsorption b) Chlorination c) Filtration

2- When chlorine is added to water it not only kills disease causing bacteria and micro-organisms, it also causes a(n) _____ reaction resulting in the precipitation of dissolved iron and manganese and the release of trapped gases as well.

a) Oxidation b) Adsorption c) Sequestration

7. Disinfection

You may want to note that when chlorine is injected into water it also causes some dissolved iron, manganese, and hydrogen sulfide to precipitate out of the water.

This term refers to the process of eliminating disease causing microorganisms such as bacteria and virus. Well water can become contaminated as a result of sewage infiltration into ground water supplies. The most common indicator of water born disease is the presence of Conform bacteria when tested by a reputable laboratory.

The most frequently used and proven method of disinfecting water is to use the powerful oxidizing capability of chlorine.

If a well is suspected of being contaminated or if the well is new, the first line of defense is to disinfect the well itself using the following procedure.



1. Remove the well cover. Pour the required amount of bleach into the well. SEE TABLE BELOW.

2. Run ALL FAUCETS in the house, one at a time, until you smell the chlorine at the faucet. This ensures that the whole system gets disinfected.

3. Connect a garden hose to an outside tap or an indoor tap with the correct threaded filling. Put the other end of the hose into the well, turn on the faucet, and from time to time move the hose so that the chlorinated water bathes the sidewalls of the well casing. Do this for at least six hours. Then turn off the tap and remove the hose from the well.

4. Replace the well cover.

5. DONT USE THE WATER for at least twelve hours. Forty-eight hours is optimal. Consider taking a weekend vacation!

6. Run the water to waste but NOT IN THE SEPTIC SYSTEM for several hours, or until the chlorine taste is dilute enough to be objectionable. The best way to run the water to waste is to use the garden hose mentioned above (item 3). Direct the hose into an area where the chlorinated water will not cause environmental damage or affect the water supply of others. NOTE: To avoid pump overheating and possible damage, tum off the water when flow is at a trickle and wait at least 15 minutes before turning pump on again.

7. After a week of use, retest for bacteria.

8. In some cases, one chlorination treatment WILL NOT be sufficient. Repeat disinfecting procedures as needed.

up to 150 feet One Quart
151 to 300 feet Two Quarts
over 300 feet At least one Gallon and 1 cup crushed swimming pool tablets.

NOTE: The above table is for wells with a SIX INCHES IN DIAMETER CASING.



1. Multiply the well diameter in feet by itself. (Square the diameter).

2. Multiply this result by the depth (in feet).

3. Multiply the final number by 0.0302.

This will give you the NUMBER OF QUARTS of Bleach required for disinfection. Round off the number to the nearest HIGHER whole number to

be absolutely safe. It is better to over-chlorinate than to under-chlorinate.



New wells must be thoroughly (and often repeatedly) disinfected. The construction process usually leaves the well grossly contaminated. If a new well has not been thoroughly disinfected, pollution can persist for a long time. By following the suggestions above carefully, you can frequently achieve a properly disinfected supply after the first cleansing

As a supplement to wen disinfection the Aqua-Pure Metering Pump is recommended to provide a continued supply of sale wilier. The pump can be adjusted to feed just enough chlorine into the water to assure that disease bacteria will be adequately controlled.

The metering pump mounts on top of the Aqua-Pure chlorine solution tank and automatically draws up the chlorine and injects it into the well outlet pipe.

The metering pump is wired to the water supply pump so it chlorinates continuously as the water is run. Since chlorine requires approximately a 20 minute contact tune to disinfect water, an extra holding tank is required following the well pressure tank. To determine the proper size tank, multiply the welts pumping rate in gallons per minute by 20. Following installation, a test kit should be used to monitor "residual' chlorine thereby assure effective disinfection.

What problems will chlorine disinfection cure? In addition to providing a margin of safety to homeowners with wells, continuous chlorination can also reduce problems due to iron, manganese and hydrogen sulfide. Once

oxidized by the chlorine, these objectionable impurities, along with any remaining chlorine, can be filtered out by sediment and carbon filters from the Aqua-Pure line.



8.Membrane Separation (Reverse Osmosis)

Reverse Osmosis (RO for short) was originally developed in the 1950's under US government funding as an economical method of desalinating sea water — the most difficult water treatment challenge.

RO uses a thin synthetic plastic material called a semipermeable membrane to separate virtually all types of impurities from water including the total dissolved solids.

The RO process works by using water pressure to force water with impurities against the membrane surface. Water molecules slowly permeate through the membrane and are collected in a sealed storage container. The impurities, which are left behind or rejected, are automatically diverted to a waste drain and do not build up on the membrane as with conventional filter systems.

Reverse Osmosis Module (Membrane)

Once a membrane Is rolled into a spiral would configuration it must be property installed in a vessel which contains the flow of feed water across the membrane Reverse surface and isolates it from the pure wate



Feed Water: The main flow of impure water to be treated and which passes across the membrane surface and acts to transport impurities away.

Product Water: That portion of the feed water which pass through the membrane as pure water.

Module: The combination of the spiral round membrane element and pressure vessel.

Membranes are available In a variety of material, the most common being Cellulose Traicetate (CTA) and Thin Film Composite (TFC).

CTA Membranes otter a good combination of production rate, TDS rejection and resistance to chlorine but are subject to deterioration from high pH (pH > 8.5) and bacteria.

TFC Membranes offer the highest production rate, TDS rejection and complete resistance to both pH extremely (pH 3-11) and bacteria. The one disadvantage of TFC membranes is that they are subject to deterioration from chlorine used to disinfect public water supplies. A carbon filter must be used prior to the TFC membrane to remove chlorine.

Most RO systems used today are designed as POU under sink appliances that use a separate faucet to dispense the water. They generally produce from 5-15 gallons (18.95 - 56.78 liters) per day depending on water pressure and temperature.

Well designed residential RO systems are the preferred choice for supplying drinking water equal to the highest quality bottled waters.

Other factors affecting the production rate include the total dissolved solids and temperature.



1) The__________ method of desalinization/demineralization has been around for about 40 years and has been developed primarily out of scientific research into ways to desalinize sea water.

a) Reverse Osmosis b) Distillation c) Oxidation


2)Reverse Osmosis systems are considered to be_________

a) Point-Of-Entry (POE) b) Point-Of-Use (POU)


3)Most households reverse osmosis systems can produce between ________ and__________ gallons of water per day.

a) 5-15 b) 20-50 c) 50-80



The Aqua-Pure Reverse Osmosis drinking water system combines particle filtration, reverse osmosis and carbon adsorption in a fully automatic low maintenance design.

The components in the Aqua-Pure Reverse Osmosis System include:

Purification Assembly

Sediment Pre-Filter: A high capacity graded density cellulose fiber cartridge pre-filters the water before it enters the RO module to protect the membrane from premature plugging.

Carbon Pre-Filter: A high capacity carbon pre-filter protects the TFC membrane from chlorine.

RO Module: The heart of the system rejects virtually all classes of impurities except low molecular weight ( VOC ) organic chemicals. The Total Dissolved Solids, TDS are typically reduced over 90% where

% Rejection = Feed TDS - Product TDS x 100

Feed TDS

EXAMPLE: What is the % rejection if the teed TDA equals 400 and the product TDS is 40?

400-4 _ 360 x 100 = 90% rejection 400


The rejected impurities are continually rinsed from the membrane by a secondary stream and disposed of to drain.

Carbon postfilter — A high capacity carbon postfilter incorporating over 35 cubic inches of top grade media. It is designed to remove residual tastes, odor's and organic chemicals.

Captive Air Storage Tank — RO product water is stored in a sealed synthetic bladder housed in a protective metal shelf. As the bladder fills, air is compressed. When the customer opens the faucet the compressed air forces the RO water out through the faucet.

Chrome faucet — Thin RO faucet is the most attractive and rugged available. ft mounts in the sink ledge or countertop and includes an approved air gap designed to meet local and regional plumbing codes.

What drinking water problems will the RO cure? The APRO-5000 will reduce the TDS by over 90% and by doing so give the customer the ideal water for cooking, drinking and ice cubes, which greatly improve in clarity. The RO system will also remove a number of heath related contaminants such as nitrates and lead (please refer to product data sheet).

What about Maintenance?

The Aqua-Pure RO system requires periodic maintenance as outlined below. Since local water conditions vary considerably, especially in sediment and chlorine, the frequency of filter replacement is recommended within a range.

Sediment prefilter = 6 months - 1 year

Carbon prefilter = 6 months - 1 year

RO module - Replace based upon % rejection test when < 75%. Service life is typically 2-3 years.

Carbon postfilter= 1 year

System/tank sanitization =1 year

Tank air charge check = 2 years

9.Demineralization (Deionization)

Demineralization refers to any ion exchange process that removes all and only dissolved mineral soils (TDA) from water. Unlike softening, which only substitutes salt (sodium) for the cations such as calcium and magnesium, demineralization uses two types of ion exchange resins to remove both cations and anions.

These include:

* chlorides • bicarbonates

* sulfates • nitrates

* carbonates

The demineralization process is rarely used for POU and POE systems because of its limited capability, small capacity and high operating expense.





The distillation process is one in which water is converted to its vapor state by heat, leaving a broad range of impurities behind, they are condensed back to liquid state and collected for use.

POU distillers are generally electrically heated and are costly to operate

(three kilowatt hours per gallon) when compared to reverse osmosis systems. A combination of high maintenance and flat taste of the distilled water have prevented them from having wide consumer acceptance. High quality distillers however are the preferred choice when a water supply is of unknown quality and may contain harmful microbiological contaminants.

We have covered a lot of ground and given you a great deal of Information. Let's rotor to the chart below to help review and organize the highlights of what we just covered.




Red/brown staining of bathroom fixtures and laundry; metallic taste in water 

- Ion Exchange 

- Oxidation/Filtration 

- Water Softener  

- Iron Removal System 

- Metering Pump 

Blue/green deposits on sinks and bathtubs; corrosion and pitting of fixtures. 



-Acid Water Neutralizer 

-Metering Pump 

-Scale/Corrosion Inhibiting Filter 

Scale formation on faucets, 

glassware, water heaters ft water heater elements; difficulty 

lathering soap. 


Ion Exchange 

-Scale/Corrosion Inhibiting Filter 

-water Softener 

Visible particles and unclear water; sediment; dripping faucets. 


Dirt/ Rust Filter 

Brackish, metallic, or chlorine taste to water; off tasting beverages. 



-Reverse Osmosis System 

-Activated Carbon Filter 

-Drinking Water System 

chlorine taste; swampy, musty,  
unpleasant taste and odors. 


-Drinking Water System 

Activated Carbon Filter 

Rotten egg smell. 



-Metering Pump 

-Activated Carbon Filter 



Metering Pump 

Giardia Lamblia 

Submicron filtration 

Drinking Water System 

When water problems are multiple and present a variety of troubling symptoms at the same time, it is sometimes necessary to combine two or more treatment processes together in a sequence to solve the problems. Another factor in determining the treatment process is the severity of the problem. Most minor water quality problems can be effectively treated with Aqua-Pure' water filtration systems. As the levels of severity increase, it becomes necessary to move to larger water treatment systems to solve these more complex water quality problems. The final factor in determining the necessary treatment process is the amount of treated water that is required, and the degree to which the customer needs to go to feel that the problem is resolved


1. Testing the Waters:

One of the best things you can do for your customer and for yourself is to listen to your customers description of the problem, and then actually conduct a water analysis. The results of the analysis will enable the customer to understand the cause and severity of their problem. For you, the test results guide your selection to the correct product for resolving their problem. If it is a single problem, your solution can be direct and simple. If the problem has multiple causes, the test results will give you the hard data necessary to explain to the customer why several processes or pieces of equipment are needed to cure the problem. Water analysis eliminates guesswork, and reduces potential mistrust on the part of the customer.

What is The Residential Water Quality Audit ?

To make it easier for you, CUNO has developed a Residential water Quality Audit Form and included it in your manual. This form will take you through all the steps of the in-home analysis and give product recommendations for specific problems. Make sure you complete all steps in the Water Quality Audit and always carry these forms with you when you are on a call to be sure you have completed the Residential Water Quality Audit properly. Water testing is heavily dependent upon having a valid water sample. That sounds simple enough, but actually, taking a valid water sample is not so easy. The goal is for the sample to accurately reflect the water condition. There are several factors that can throw off the validity of a sample. For instance, when testing well water, if the water is not run for a long enough period of time, the sample will reflect the conditions of water that has been sting in a pipe or pressure tank, rather than the actual water condition. Another example is exposing the sample to open air (oxidation) and high temperatures. This will allow hydrogen sulfide gas to escape into the air, thereby reducing the amount of hydrogen sulfide remaining in the water.


For best results, water samples should be taken from a gentle flow of water that has been run for several minutes. Plastic sampling bottles are preferred. Manganese, for example, adsorbs on the surface of glass containers and invalidates the test results by causing a lower than actual reading level. The sample bottle should be slowly filled until it overflows. It should immediately be tightly capped with as little air as possible. Testing should then be done as quickly as is practical.

Water testing used to require that the sample be sent out to a lab for analysis. While these labs are still relied upon for more complex problems, CUNO offers on-site test kits for the more commonly found problems. These kits are inexpensive, and easy to use and interpret. Simple dip and read strips will

change color depending upon the water contents. The colored strips are then compared with a color chart that indicates whether the problem exists, and it it is excessive.


CUNO Water Test Strips can measure all of the following conditions:

• Hardness, pH • Chlorine, Chloramine • Alkalinity.


The Aqua-Pure Master Test Kit is available for testing pH, hardness, iron,



1._______ tends to absorb on the surface of a glass water sample bottle, thus invalidating the water test results.

2. Water testing is heavily dependent upon having a _______water sample

3. When testing well water, you should take the sample only after allowing the water to run for several minutes.

True _____ False______

4. A water sample bottle should always be filled only halfway.

True _____ False______

5. Aqua-Pure Master Water Test Kits use dip and read strips.

True _____ False______

Here are some general suggestions to help you make the appropriate product selection.

* Always recommend an Aqua-Pure Dirt/Rust Fitter for protecting the entire household plumbing system.

* Consider recommending the Aqua-Pure Taste/Odor Fitter as a standard piece of equipment for all kitchen and bathroom faucets.

* For low to moderate levels of hardness, recommend the Aqua-Pure Scale/Corrosion Inhibitor Fitter. For moderate to high levels of hardness, suggest the Aqua-Pure Water Softener.

* For water with iron and/or manganese present, recommend the Aqua-Pure Iron Removal System.

* For water with a pH between 5.5 and 6.8 recommend the Aqua-Pure Acid Water Neutralizer. With pH levels below 5.5, recommend the Aqua-Pure Metering Pump. For pH levels above 6.8, recommend the Aqua-Pure Scale/Corrosion Inhibitor Filter.

* dissolved solids or other impurities, recommend an Aqua-Pure Chemical Removal Filter, Drinking Water System or Reverse Osmosis System.

2. Sizing a Filter or Treatment Unit:

Now that you are able to test the water and recommend a solution, ifs time to size the fitter or treatment system to lit the customers need. There are several factors that should be measured: we will examine each separately.

* Peak Flow Rate/Service Flow Rate

* Fixture Load Values

* The Severity of the Problem

Peak Flow Rate

Peak Flow Rate is the amount of water that plumbing pipes, valves and fittings will allow to flow without excessive pressure drop. Pipe size can often times be used as a good indicator of the peak flow rate for a plumbing system. The following chart shows the relationship between pipe size and peak flow rate.

Typical Flow rates at 60 PSI (4.1 Bar) on Unrestricted Lines 

Tubing ID 






Flowrate GPM (LPM) 

 1.2 (4.5) 

 2.75 (10.4)  

 4.9 (18.5) 

 7.63 (28.8) 

 11.0 (41.6) 

Pipe size (Sch 40) 











Flowrate GPM (LPM) 

2.5 (9.5) 

4.5 (17.0)  

7.5 (28.4)  

12.0 (45.4)  

20.0 (75.6) 

36.0 (363.3) 

48.0 (181.4) 

80.0 (302.4)  

125.0 (472.5) 

200.0 (756.0) 



1. The factors involved in sizing a filter unit or treatment system are_____ , the fixture load values, and the severity of the problem.

2. _______ can be a good indication of peak flow rate.

Service Flow Rate

Service Flow Rate is the amount of water that a plumbing fixture will allow to flow while maintaining optimal operating performance. Ideally, the service flow rate of a filter unit treatment system should be at least equal to the Peak Flow Rate. However, the actual peak flow requirements will depend upon the number of people and the number of water using fixtures and appliances in the house. Typically most households are served by a 3/4" (19 mm) incoming water line. According to our chart, that means a Peak Flow Rate of 12 gpm (45.4 Ipm), and prudently, a service flow rate on the filtration unit or treatment system of 12 gpm (45.4 Ipm). In reality, however, if there are only 3-4 household members, a filter unit or treatment system with service flow rate of 6 gpm (22.7 Ipm) could be acceptable. Heavier contamination and more people would require the use of units with service flow rates of 12 gpm (45.4 Ipm).


Fixture Load Values

Fixture Load Values: In residential and commercial buildings, each water using fixture and appliance has a 'Water usage load value." This load value relates to the amount of water that is required to operate the fixture or appliance efficiently. (You should note that private and public facilities have different load values, and that the flush tank system requires less water than the flush valve system.) In order to determine a properly sized water filtration or treatment system, it is necessary to identify all of the water using fixtures and appliances in the building. Then refer to the following table to get the water usage load value for each appliance and fixture. (See Chart 3.) For example, a private water closet with a flush tank has a load value of 3. See e you can find it Okay? Good! The next step is to add the load values for each household fixture and appliance to get a Total Load Value. Using the Total Load Value number, we now go to the following table for estimating the Total Water Use. (See Chart 4.) Suppose our Total Load Value is 16. Using the table, we can see that the corresponding Demand is 18 gpm (68 torn). Since 70% of the estimated Demand is generally sufficient to support flow requirements, then the Total Water Use would be 12.6 gpm (22.7 lpm) (18 gpm/.70 = 12.6 gpg). Therefore, the recommended fitter unit or treatment system should have a service flow rate of at least 12 gpm (45.4 lpm).

How Severe Is the Problem?

How Severe Is the Problem? Would you characterize it as moderate or heavy? If it is a heavy problem and you are suggesting a filter cartridge, for instance, you may want to oversize the filter unit (twice the service flow rate needed). this will extend the time between fitter cartridge changes and will actually extend the life of each cartridge. You may also have a water problem that calls for a combination of products to arrive at an effective solution. For instance, suppose you had selected a water softener to eliminate the problem of hard water. Your test for iron, however, tums out with a measurement of more than 3 ppm. You know that high levels of iron can damage the resin bed of the water softener, so you would insist upon having a correctly sized Aqua-Pure Iron Removal System installed ahead of the water softener.




1. represents the amount of water that is required for a fixture or appliance TEST to work efficiently. True False

2. Most households are serviced by a 2"/5.1 cm incoming water line. True False









Water closet 


Flush valve 



Water closet 


Flush Tank 



1* Flush valve 





3/4* Flush valve 



Flush Tank 









Shower head 


Mixing valve 

Service Sink 

Offices, etc. 




Kitchen Sink 

Hotel, restaurant  


Drinking fountain 

Offices, etc. 

3/8* value 



Water closet 


Flush valve 

Water closet 


Flush Tank 











shower stall 


Mixing valve 



Kitchen Sink 





Laundry trays (1 to 3) 





Combination fixture 





Dishwashing machine 



Laundry Machine (8 lbs.) 





Laundry Machine (8 lbs.) 

Public or general  




Laundry Machine (16 lbs.) 

Public or general  


3. Installation Considerations:

When installing an Aqua-Pure filtration or treatment system, there are some practical considerations to think about. These are given to you to encourage you to pay careful attention to the product installation specifications and requirements that accompany each product. These conditions relate closely to the proper operation/ maintenance of the equipment.


Check the pumping rate and water pressure in the house

For example, the pumping rate of a well must be sufficient for the satisfactory operation of the backwashing cycle of an Iron Removal System or Water Softener (rates vary for different units). Also, the water pressure specification should be noted. A Water Softener requires a minimum pressure of 20 psi (1.38 bar), while a Reverse Osmosis unit might require a minimum pressure of 40 psi. High end water pressures are also important, in that pressure over 100 psi (69bar) will require the installation of a pressure reduction valve when installing a water filter or treatment system.


Location Consideration

Always allow sufficient space around the installation for easy servicing and cartridge replacement. Locate the filter unit or treatment system in the correct sequence. For example, it is necessary to locate a scale/corrosion inhibitor filter BEFORE the water heater, since water temperature above 100°F (38°C) will damage the filter cartridge. Care should also be used to avoid placing units in areas where freezing may occur.


Electrical Consideration

On those treatment systems requiring electrical power, make sure to provide a non-switched (usually 110/120 V 60 Hz) power source. Also 11 the existing plumbing system is used as the ground leg at the electrical supply, continuity should be maintained by installing ground straps around any non-conductive plastic piping used in installation.


Consult product specifications and requirement

For all water filtration units and treatments systems, be sure to consult the specific product specification and requirements to make correct installation.