It is desirable and possible to maintain sparkling clear sanitary conditions in your pools water.  To attain and maintain this optimum water condition, you must consider the three factors that make it possible; CHEMICAL, BIOLOGICAL and MECHANICAL. Pure water is a tasteless, odorless, colorless compound. If natural water were pure and contained no suspended or dissolved matter, and could be maintained in this condition, there would be no need to test, analyze and treat swimming pool water. However, all water contains some impurities, either in solution (invisible) or suspended (visible).  Water testing detects these impurities while filtration, chemical balance and biological treatment controls them. Impurities in the water, whether entering the pool in the fill water, from the environment, wind blown atmospheric wastes, or swimmer waste are either dissolved in solution or suspended particulate impurities.  Suspended particles can be organic or inorganic.  They are visible (cloudy, fuzzy or dull appearing water) and should be removed by filtration. Dissolved impurities cannot be seen and are not removed by the filter without chemical aid. To assist the filter in removal of organic waste particles (Sunscreens, oils, hair sprays, cosmetics, dead skin, etc.) the chemical balance of the water must first be kept at an excepted level.

REMEMBER: It is not the water itself that has to be treated, but the various impurities in the water. To maintain quality pool water, you have to relate water chemistry to all three factors related to pool maintenance. For example, if the pool filter is dirty or not working properly, or circulation is not getting all of  the water to the filter, the water clarity will be poor and chlorine usage will be greatly increased.  This situation can cause poor sanitation and increased chlorine consumption, which increases costs.  This indicates that not only should you perform routine maintenance (backwashing or cleaning the cartridge), but also clean the internal filter media and look for possible filter or pump damage.

​

CHEMICAL FACTORS

 

PH is a very significant factor and exerts the most influence on the scale formation or corrosives of your sanitizer (chlorine/bromine). The Ph of your pool water will determine the efficiency of the sanitizer.  We define Ph not as the measurement of the total amount of acid or base in a pool, but as a measurement of the "activity" of the acid or alkali present. Acids are chemicals that form Hydrogen Ions ( H+) when dissolved in water.  Bases<Alkaline materials> are compounds which form Hydroxyl Ions (OH-) when dissolved in water. Thus, the term Ph stands for "Possible Hydrogen Ions". When you have a high Ph it can causes cloudy water, poor or no sanitation, scale formation on the walls, clogged filters (due to scale formation), damaged heaters, mineral staining, algae growth and eye irritation.  If you have a low Ph you could get corrosion and rusting, rapid loss of sanitizers, wrinkling and damage to vinyl liners, and eye irritation. Ph is a very important factor as you see and should always be taken serious at all times of the year. The Ph scale runs from 0 to 14. A Ph of 7.0 is considered neutral.  Values below 7.0 are acidic, Ph values above 7.0 are consider to be basic.  The suggested Ph range for pool water is 7.4 to 7.6, ideally the Ph of your pool should be 7.4. MARATIC ACID can used to lower the pool's Ph. Aeration and Sodium Bicarbonate can be used to raise PH. 

​

TOTAL ALKALINITY (TA) refers to the amount of alkaline materials in the pool water. These alkaline materials act as buffering agents and help control Ph. If the TA is too high, changing the Ph is difficult because the water resists Ph changes.  High TA can also cause cloudy water, mineral stains, eye irritation, chlorine inefficiency, and calcium scaling. Water with low TA is sensitive to Ph changes, and  will bounce" from high to low Ph as you try to adjust Ph. Water with low TA also tends to be corrosive, irritating to eyes, etching in concrete and plaster, corrosion of metal fittings, and can be colored (usually light green). The suggested TA for vinyl-lined pools is between 80 and 120 ppm.  Since TA has an effect on Ph, it is normally adjusted before any Ph adjustment is made.  If the TA is below 100 ppm and Ph is above 7.2 you can raise the TA by adding "BICARB.", If the Ph is below 7.2 add “Soda Ash” to raise Ph to proper level first. When increasing TA, the water may become temporarily cloudy for a few hours, but will clear.  However if adjustment is needed Muratic Acid is the chemical that is used to lower TA.  If the pool has a very high TA it may take many treatments to lower.  When acid is added to pool water with a High TA the TA level is reduced. Also, there will be a small drop in Ph.  Since a high level of TA still remains, the Ph will bounce back up to its original level. Because of this treatments for TA should be spaced at least 12-24 hours apart to assure proper test results. 

​

CALCIUM HARDNESS refers to the amount of calcium and magnesium carbonate <plus other minerals> in the water. In pool water, we are mostly concerned with the calcium carbonate level or calcium hardness (CH).  It should be tested for and adjusted to balance with the total alkalinity of the pool water.  Although "soft" water (low CH) is considered better for regular household use, soft water is not desirable in swimming pools as it is corrosive and damaging to your pool.  Low CH causes the water could be corrosive.  High CH can lead to scaling, clogged filters, bleached appearance of liners, heater damage, and cloudy water. Maintain CH at 250 to 400 ppm for vinyl-lined pools. To raise CH, add "CALCIUM HARDNESS" after dissolving the required amount in 2 to 3 gallons of pool water.  Lowering CH is not as easy, partial drain and dilution of fresh water is required. As pool water evaporates, the minerals stay behind and become more and more concentrated, increasing CH. If the CH is always high in your pool (above 450 ppm) consult your local pool store or pool service company for assistance.

 

IRON, COPPER, and MANGANESE present in water is what generally causes the water to be colored. They can be present as metallic ions in solution which is associated with well waters, or as finely divided particles of metallic compounds in suspension which are associated with surface waters.  When a pool has a high reading of metallic ions in solution make certain that the Ph of the pool is not raised above 8.2 as this will cause the metal to plate on the walls of the pool which will cause staining.  Each type of metal imports its own characteristic color to the water when oxidized by chlorine or bromine. Iron produces a reddish or reddish-brown tint; copper causes the water to appear blue-green and, when manganese is present the water takes on a dark brownish-black hue. The presence of 0.3 ppm iron or 0.3 ppm manganese, or any combination thereof, WILL stain white goods or white steps of a swimming pool rapidly.  0.2 ppm,0.1 ppm will stain, but it takes just a little longer to react. Even a trace of a metallic ion will cause unsightly stains. These may be avoided by using a stain preventive at the time of filling or refilling by adding a sequestioning agent.

 

Sanitation Pool water sanitation simply means killing bacteria and algae in order to disinfect and clean the water.  Many sanitizing substances are available, but few are safe and effective for swimming pool use.  Sanitizers used in pools must provide a residual chemical level once the algae and bacteria have been killed.  It is this residual which is ready to kill any new bacteria which enters the pool, keeping the water safe for swimming.

CHLORINE in its various forms is the most commonly used pool disinfectant.  In addition to killing bacteria, chlorine helps to kill algae and destroy waste material not removed by the filter system.  In its natural or elemental state, chlorine is a gas.  But chlorine gas is very toxic and hard to handle safely.  This is why chlorine is combined with other compounds to form several liquids and solids which are effective sanitizers and safer to handle than chlorine gas. No matter what form of chlorine you use, it's primary purpose is to combine with water to form what is called FREE CHLORINE or "Hypochlorous Acid"(HA) .  It is only the chlorine in the form of HA that sanitizes and disinfects. Over 90% of the sanitizing power of any chlorine comes in form of the all important HA.  HA has certain limitations. It tends to be unstable in the presence of sunlight, high temperatures and high or low ph levels. These conditions cause rapid chlorine loss.  The amount of Hypochlorous Acid (disinfectant) your chlorine forms is dependent on the pool water Ph.  As the Ph increases, the percentage of chlorine that forms into disinfectant decreases.  For example, at a Ph of "8", only 23% of the chlorine is forming disinfectant. This is one reason why Ph should be monitored.  All swimming pools can develop "CHLORINE DEMAND" when insufficient chlorine is present. Dissolved iron, bacteria, perspiration, algae, pollen spores, and other organic materials create a "CHLORINE DEMAND" in pool water.  If enough chlorine were added to form the suitable amount of HA to oxidize all of the pollutants present, a "CHLORINE DEMAND" would no longer exist.

​

 KINDS OF CHLORINE

​

Calcium Hypochlorite is a dry "Unstabilized" granular product with a calcium base.  It is 65% available chlorine with a Ph of 12 to 13.  It is slow dissolving and should be dissolved in a bucket of water prior to adding to the pool. Constant use of a calcium based chlorine will increase the calcium hardness and cause the Ph to climb upward.  In the presence of heat and sunlight, it is relatively unstable and precipitates out of the water rapidly.  

 

Sodium Hypochlorite is a "Unstabilized" liquid chlorine used in many large commercial as well as smaller private pools where handling and storage is not a problem.  It has 10% to 15% available chlorine with a Ph of 13 to 14.  It does not store well in heat or sunlight and should be used as soon as possible after it is manufactured.  The best results are obtained when it is fed automatically through a sodium hypochlorite feeder directly into the water lines.  When in the pool water, liquid chlorine is adversely affected by sunlight. For this reason it is best if you only use liquid when a well balanced Stabilizer reading is present.  This product is sold fresh at 12-15% available chlorine at your local pool store or in 8 to 11% version at your local hardware store in 1 gallon jugs.

​

Lithium Hypochlorite is an "Unstabilized" granular fast dissolving material with 35% available chlorine and a Ph of 2 to 3.  It is not generally available in all parts of the country and is used primarily as a shock treatment.  Most stores do not carry this type of chlorine due to its high cost.

​

Sodium Dichloroisocyanurate is a "Stabilized" granular chlorine with 56% to 62% available chlorine and a Ph of 7. It is highly resistant to sunlight and heat, thus remaining in water much longer that the previously mentioned chlorine. It can be hand fed or pre-dissolved and pumped through a sodium hypochlorite feeder.  Although mostly used in private pools, it is becoming more popular for commercial pool applications. 

​

Sodium Trichloroisocyanurate is a "Stabilized" tablet or stick form of chlorine with 90% available chlorine and has a Ph of 2 or 3.  It is usually fed by means of a floating chlorinator or a by-pass type erosion feeder  connected to the return lines of the filter system. It is a chlorine that is resistant to sunlight and has a relatively long life in the pool water. We only recommend using Trichlor tabs in an automatic chlorinator "by-pass erosion feeder" located at your pool equipment. 

 

BIOLOGICAL  FACTORS

​

Algae: Algae are small plants which may be found growing in swimming pools or other bodies of water whenever conditions are favorable to their growth,  they may retreat into inactive particles that are carried about by the wind, which may blow them to another body of water.  The atmosphere contains millions of these minute particles ready to infect a pool.  Rain washes algae from the air into swimming pools.  Allgae can originate, grow, and reproduce in a matter of hours, <NOT DAYS>. There are many thousands of species of algae, each species having its own resistance to various sanitizers and algaecides. 

​

TYPES OF ALGAE

​

GREEN ALGAE is a group of algae that grows on the pool walls and in the water.  They give the water a green cloudy appearance.  The walls and floor will feel slippery or slimy. This creates a dangerous environment and should be treated immediately. 

​

MUSTARD OR YELLOW ALGAE grows either on the walls or in the water.  One form of mustard algae will grow on the floor of the pool.  It will resemble silt and float free if you brush your hand over it.  Another form will start in corners and around ladders and steps to form a yellowish slimy look.  Yellow algae will most of the time seem to brush off of the walls, But that is not the case at all.  Think of yellow algae as a tiny tree growing in the pool wall, when you brush the walls you are removing the leafs off the tree.  But, the tree stem, trunk, and roots are still there so within a week or so the algae will return and get even harder to kill. You MUST use an algaecide to remove yellow algae, chlorine will not work alone. 

​

BLACK ALGAE is a rooted algae Roots will penetrate into concrete or vinyl making it extremely difficult to kill.  It will appear as small black spots and as the colony grows it will spread and appear to "bloom".  Unlike the other algae groups above this is one bad type and hard to kill.  The basic treatment has to include a wire type brush, a 1/2 pound of   Sodium Dichloroisocyanurate, and an algaecide designed for BLACK ALGAE. The brush is used to open up the protective dome the the algae builds over itself, the Sodium Dichlor is then poured on the algae so it can get into the dome, and last the algaecide is poured nearby so it can finish the job and completely kill and remove the algae from the surface.

​

MECHANICAL FACTORS

​

1>  Filtration is to remove visible particles from the water as it passes through the filter media inside the filter tank or canister.

2>  Circulation is the rapid movement of the water to insure that ALL of the pool water passes through the filter frequently enough to remove visible particles.

3>  Vacuuming is the physical removing of the heavier  particles that settle on the floor of your pool.

4>  Water Temperature can affect the corrosion or scaling problems that take place in the pool.  Temperature does  have an influence on the growth of bacteria or algae in   the pool since warm water rises carrying chlorine to the surface leaving the bottom water with poor disinfectant levels.

​

TYPES OF FILTRATION

​

HI-RATE SAND FILTER are easy to use and maintain.  Most sand filters use a sand graded to .35 to .45 millimeters in size for best filtration.  You should not backwash / backflush a sand filters until it needs to be done.  You need to use the pressure gauge to determine when to backwash. The sand filter must have a pressure gauge that is working to assure good filtration.  Pressure increase should be 8 to 10 pounds per square inch above the starting pressure before backwashing is needed.  sunscreens, suntan oils, body oils, cosmetics, iron, calcium, copper, manganese and other organic and inorganic materials cannot be removed by backwashing.  You need to use a filter cleanser  at least once a year to completely remove all of the build-up of organic and inorganic wastes imbedded in the filter sand. However studies have found that to keep a clear pool free of algae with the use of a sand filter it is recommended that you use a filter cleanser at least once every three months.  

​

DIATOMACEOUS EARTH FILTERS (D.E.) Filters use a coating of D.E. over grids to trap waste and debris.  For this filter to operate properly, it requires two ounces of D.E. powder per square foot of filter grid.  With clean grids freshly coated with D.E., you will have there lowest pressure gauge reading.  After the filter has gained ten pounds pressure, you should wash out the dirty D.E. through backwash and replace it with fresh D.E.  All D.E. filters will get organic oils and inorganic mineral deposits solidified in the weave of the grid reducing even water flow and distribution of the D.E. powder.  This means that at least twice a year, you will need to take the filter apart to clean the grids and soak in a filter cleaner for 24 hours. 

​

CARTRIDGE FILTERS have woven fan folded cartridges that trap waste and debris in the creases and within the weave itself. These cartridges will need to be removed from the filter tank for cleaning. Large debris can be hosed off with water.  Fine organic oils and inorganic mineral deposits may have to be dissolved for removal.  After hosing off large debris, soak the cartridge in a filter cleaner. 

 

CIRCULATION

​

Inadequate circulation is often ignored in pool operation. Many pool owners and operators cannot obtain clear sparkling water, even though their filters are operating properly. This may be happening because all of the pool water is not passing through the filter, but a portion of the same water is going to the filter time after time. 

 

VACUUMING AND BRUSHING

​

Even though you may now have good filtration and circulation, which removes the majority of the debris, we still have another physical task.  Some organic and inorganic particles may attach themselves to the pool walls or "fall" to the floor where they will have to be brushed or vacuumed off.  Vinyl-lined pools, being of a smoother finish, probably will not need to be vacuumed as often. If there is an automatic cleaner of the type that climbs up the walls in use this problem is non-existent. The lack of such a cleaner will require you to brush the walls and vacuum the floor of the pool at least once a week to stop the growth of algae and the formation of stains over the surface.