Pool and Spa Care Tips
Aqua Mechanics, Inc.
Products and Services for all your Pool and Spa Needs
328 West  Lee Highway
Warrenton, Virginia  20186

phone: 540-341-7665
fax:      540-341-0947

email:  info@aquamechanics.org
Pool Care 101
Pool Anatomy

It is important that every pool owner knows how a pool functions.  Refer to the diagram accompanying this text to develop an understanding of how a pool system is designed to operate.
The pool equipment and plumbing are designed to keep water moving. The suction-side of the system pulls the water from the pool to the pump. The pressure-side of the system delivers the filtered (and sometimes heated) water back to the pool.


The Suction Side:

Skimmer(s) draw water from the surface of the pool and capture floating debris into the
skimmer basket.

Main Drain(s)   (Bottom Suction) draws water and debris from the bottom of the pool. Its primary function is to circulate the water in the deepest part of the pool.

Suction lines transport the water from the skimmer and main drain to the equipment location

Three-way Valve (Control Valve), positioned where the suction lines come together, lets you control where the water is coming from…the main drain(s), the skimmer(s), or a combination of both. This valve (or valves) is essential in order to isolate equipment for maintenance or to improve the circulation of the water.

The Pump is the transition point from suction to pressure. Positioned in front of the pump is a hair and lint basket. It captures debris that the skimmer basket missed or debris pulled from the main drain. The hair and lint basket should be inspected and cleaned regularly to allow the free flow of water into the pump housing. Once the water is pulled into the pump by the impeller, the transition from the suction side of the system to pressure side is complete.
The Pressure Side:

•The Pump and Motor are the heart of the pool system. The impeller, within the pump creates centrifugal force, which pulls the water through the suction side of the system. Once through the pump, the water if forced (pushed) through the pressure side of the system.

The Filter is the first piece of equipment to receive the water from the pump. The filter (Sand, Cartridge, or Diatomaceous Earth [D.E.]) strains the water and captures both large and small particles. A properly sized and operating filter is critical to keep water clean. As the filterable debris is collected on the surface of the filter, routine physical cleaning is required. Some of this debris is capable of being washed off, but a lot of debris can only be removed by chemically cleaning. Each type of filter is designed to allow physical “washing” of the media. Sand and some D.E. filters utilize a control valve to reverse the flow of water through the filter in a process called backwashing.

The Heater is an optional piece of equipment, which warms the water before it’s returned to the pool.

•Return Lines transport the water from the filter/heater back to the pool.

The Return Valve(s) allow you to control the flow of water returning to the pool. On some pools it may be necessary to isolate the equipment from the pool in order to perform maintenance on the equipment. Additionally, some pools may have a water feature installed on the pool, like a water fountain, waterfall or spa jets in the steps. This return valve can be adjusted in order to feed water to these features.

Return Inlets feed the water into the pool. Ideally, these inlets should point slightly downward to push the water toward the bottom of the pool and achieve the most effective circulation.

Algae Problems

Green Algae  is a common swimming pool problem, which may appear as a greenish growth on the floor and walls of a swimming pool, a green tint to the pool water, or greenish material suspended in the pool water. The only swimming pool chemical that will kill an algae growth is chlorine based swimming pool "shock". Shock is  highly concentrated chlorine, which quickly raises the chlorine level of the swimming pool water. The elevated chlorine level makes the pool water conditions unlivable for anything organic, and algae quickly dies. There are certain steps that must be followed to elliminate the algae. Stop by the store and let us help you get rid of your algae problems.


Mustard algae is a yellowish green color.  In its early stages it can look like small patches of sand or pollen on the bottom of the pool. It brushes away very easily, but comes back quickly. In more extreme cases, it can turn the entire pool a pea green color.

Mustard algae is a resistant strain and easily reinfests the pool through bathing suits, automatic cleaners, nets, poles, brushes, floats and other equipment or toys that were used in the pool while the algae was present. It’s important to chemically clean all of your equipment with a solution of chlorine and water and put these things in the pool while you are treating for the algae in the pool. Wash bathing suits with a detergent and bleach if possible, before wearing them in the pool again.
Mustard algae needs to be treated with a special algicide as well as chlorine. Call us or stop by and we'll help you eliminate this difficult algae.

Mustard Algae
Black Algae usually forms in cracks and crevices on pool surfaces. One of the most distinguishing features of black algae is its rough texture. It forms a skeletal growth on top to protect itself, which makes it almost impervious to normal levels of chlorine. To eliminate Black algae, you must brush vigorously to remove this protective cell coating before applying the recommended products.
If you have a black stain on the pool surface and it does not have any texture, but feels smooth, it is likely that the problem is not black algae. It could be a metal stain, or in cases where the surface is vinyl, it could be a fungus underneath the liner. To determine the nature of the stain if it does not have a texture, put some Lo ‘N Slo in a sock and hold it directly on the stained area for one minute. If this lightens the stain, it is a metal staining. If this does not work, you may try to hold a chlorinating stick or tablet on the stained area for one minute (in chlorinated or brominated pools only). If this lightens the stain, it is organic.

Banish and Spot Kill are both recommended for black algae in a chlorine or bromine pool. Application is proceeded by vigorous brushing to remove the protective exoskeleton for the top of the algae growth and superchlorination.

Black Algae
Water Mold
Pink Slime, also called "Red Algae" is not algae at all. It is a mixed growth of bacteria and other microorganisms and can also be clear to whitish in color. It is a nonpathogenic slimy pink growth. Pink slime tends to grow in areas of poor circulation and on plastic. Some common areas of pink slime buildup in pools are underneath ladder treads, inside the skimmer baskets, on skimmer doors, on return fittings, behind the light niche, and in cracks and crevices around steps and seams and tile grout.

.Phosphates, Nitrites & Nitrates

What they are & what they do:

Phosphates & Nitrogen are 2 naturally occurring elements in nature.  Phosphorous is a mineral & nitrogen is a gas.  In nature, they don't cause or contribute to pool problems.  However when they are "added" to the pool water, problems can arise -- especially in a poorly maintained situation. 

The two most significant problems are moderate to severe algae blooms and chlorine demand.  Both elements are essentially set up as a buffet table for any algae to just come, eat & thrive.

Phosphates typically come into the pool from lawn care products; fertilizers, sprays, etc.  Phosphates can also come from dead skin cells! (Therefore, another good reason to shower before entering the pool.) These lawn care products can be brought in from people walking on freshly treated areas where they are literally walked into the pool.  They can also "drift" in when sprayed or just due to a windy day.  Remember, phosphates can come from your yard, your neighbor's yard or even from someone you don't even know who lives 3 blocks away.

Although difficult to completely eradicate, phosphates can be controlled by using phosphate removers such as Natural Chemistry® Phos Free®.  Keeping phosphate levels low can aid in controlling algae (phosphates are a natural food source for algae).
Nitrogen can also come into your pool from lawn care products, but more typical, it's a case of sweat (shower before using the pool), urine (use the facilities before going into the pool) or other types of ammonia (ammonia is comprised of Nitrogen & Hydrogen - NH4).  If your local water supplier is using chloramines to sanitize the water, then large amounts of ammonia & therefore nitrogen are getting into the water.  Algae loves both nitrogen AND phosphates (phosphorous).

Here's the typical scenario with Nitrogen.  Nitrogen enters the water & combines with oxygen to form Nitrites (NO2).  The nitrogen will typically take the oxygen from the HOCl (hypochlorous acid - the form of chlorine that kills bacteria & algae) thereby causing a Chlorine Demand. You will have a difficult time maintaining chlorine, algae will thrive, the water will become cloudy, etc.  Once the nitrites have taken on more oxygen & become Nitrates (NO3), they are there to stay.  The only way to remove Nitrates from the water is to drain & refill with fresh water that is hopefully not contaminated with Nitrites.  Shocking & oxidizing will help to a certain degree.  Nitrates (NO3) you can live with, Nitrites (NO or NO2) are the problem causers.

With either Phosphates, Nitrites or Nitrates present, as long as a good, solid chlorine or bromine level is maintained, there normally isn't a problem.  However, when the chlorine is stressed out due to high bather loads, parties, rainstorms, etc. or if there is an existing chlorine demand problem, phosphates & nitrates just feed right into any algae present & the problem worsens significantly.

Treating the problem:
1.  Maintain good water balance - pH 7.4 - 7.6, total alkalinity 125 - 150 ppm, calcium hardness 200 - 250 ppm.
2.  Maintain a good chlorine or bromine residual in the water.
3.  Shock the pool (BioGuard® Burn Out Extreme®, Smart Shock® & Oxysheen® -- especially with bromine--are good products) & add algicide (BioGuard® Back Up®, Algae All 60®) weekly.
4.  Have a chlorine demand test done twice per season.
5.  Make sure swimmers & bathers shower before using the pool.
6.  If you know or suspect phosphates  have been introduced into the pool, PhosFree® from Natural Chemistry® is a great product that will remove the phosphates from the pool water, thereby depriving the algae of one of it's significant food sources.

To Make Your Chlorine Experience Fantastic, add Optimizer Plus® to create a level of 30 ppm to 50 ppm.  Using Optimizer Plus ® will significantly reduce your Smart Stick® consumption and provide the wonderful, soft feel that is associated with biguanide treated pools.

Phosphates, Nitrites and Nitrates.Used by permission of Par Inc. of Conn, Par Pool & Spa, www.parpools.com
Pink Slime
Algae Prevention

The best way to prevent algae growth in any type of pool using any type sanitizer, is to maintain the pool properly. It is important to maintain a sanitizer level at all times. Shock the pool as recommended according to your maintenance schedule. If it rains, you may want to shock again. Apply a maintenance dose of aligicide every other week (or weekly, depending on the algicide used). It is also very important to perform physical maintenance on the pool. Brushing the pool weekly will eliminate air pockets that form and promote algae growth. It also eliminates some dirt and debris which may bring algae into the pool. Automatic cleaners DO NOT perform this function. They will eliminate visible dirt, but there are still areas they miss. For best results brush the pool surface once a week.
Chlorine Demand

Definition of Chlorine Demand

High chlorine demand is the inability to keep adequate chlorine in pool water, even though the water is balanced and properly maintained. Various contaminants increase oxidation levels, consuming chlorine faster than it can be replaced by automatic feeders or normal shocking. Symptoms include slimy or slick pool walls and cloudy water (although water can be clear and still have a high chlorine demand). A sudden drop in cyanuric acid can be an indicator that there is a chlorine demand problem, as the CYA reading is often masked by the demand. If this occurs, do not add stabilizer.

Another form of chlorine demand is a high level of combined chlorine that cannot be broken by successive shock applications. Often this is caused by the presence of ammonia in the water. This can come from fertilizers, pesticides, and even fill water.

High chlorine demand can be frustrating to solve. It may be caused by a number of factors and is especially common during spring start-up. For outdoor pools subject to many environmental factors, it may not be possible or feasible to isolate the exact cause. However, this is less important than beginning immediate elimination.

NOTE:  A zero chlorine reading does not necessarily indicate that there is no chlorine in the pool. The chlorine level may be so high that it is bleaching the color out of the reagent.

Common causes of Chlorine Demand
Chlorine resistant algae, fungus or bacteria: An infestation can exhaust normal chlorine levels and require a specially formulated algicide to solve the problem. Often, the growth is not visible on the pool surface itself. Pink slime and water mold are notorious for growing first inside lines, skimmers, and behind light niches before becoming visible. Growth in these areas can continue to deplete chlorine levels steadily until removed.

Nitrogen contamination:  Lawn fertilizers and other nitrogen products in pool water produce a high level of chloramines, which require larger amounts of chlorine for oxidation.

Source water: Lake water is usually contaminated with algae, metals, and other debris, and should not be used to fill pools. Well water may have some of the same problems. Even local municipal water supplies can create high chlorine demand, especially if the contain chloramines. Every time fill water is added to the pool, chloramine and nitrogen levels rise, requiring more chlorine. Shocking after fill water addition helps prevent excessive chloramine levels in this situation, as does avoiding the addition of large amounts of fill water at a time.

Rain and Pollution: Contaminants from factories, highways, airports, and other sources may be deposited in pool water, especially during rainfalls. Clouds sometimes transport pollution over long distances. Rain and wind also carry algae spores, leaves and other debris which raise chlorine demand. During the winter, stagnant water in uncovered pools exposed to air, rain, and snow often develop chlorine demand problems.

High bather loads: A large crowd using the pool over a few days can introduce a lot of undesirable compounds, (such as perspiration, cosmetics and suntan oils), into the water. Requiring all swimmers to shower before swimming can help prevent this. Shock after any heavy bather load.

Eliminating Chlorine Demand

The best way by far to handle chlorine demand is to perform a chlorine demand test. This test is contained in a separate lab available to BioGuard Dealers. This test can give the exact amount of chlorine needed to break the demand. In some cases, this may be quite high. It may be a more feasible option to perform a partial drain and refill with fresh water to reduce the demand., Performing this test can prevent a great deal of frustration by allowing you to make an educated product application.

Prevention of Chlorine Demand

To prevent chlorine demand, maintain proper chlorine residuals consistently, shock regularly, and avoid contaminating the pool with chemicals or foreign objects.

Vacation Algae Prevention

If you will be gone for several days or weeks during the summer, balance and shock the pool before you leave. Circulate the pool for at least 6 hours per day and maintain normal sanitation during this time period. Before leaving add 16 oz. of Back up or SoftSwim A per 25,00 gallons for every full week you will be gone. Call us to schedule a Vacation Pool Care if you don't have a neighbor or friend who will brush, vacuum, empty baskets and check sanitation levels while you are gone.

BioFilm is used to describe some different growths that are bacterial in nature. The two most  frequently seen in pools and spas are commonly referred to as "Pink Slime" and "Water Mold."

Water Mold, also referred to as " Toilet Tissue Syndrome" is a whitish, mucous-like substance that looks like shredded tissue paper when floating in the water. The growth usually occurs when the sanitizer level has been inadequate or inconsistent. It is not harmful to humans, but it is unsightly, and can clog equipment. It also depletes sanitizer and oxidizers, which can allow other undesirable conditions to occur. Water Mold usually begins growing in the lines, and by the time it becomes visible, the growth is often quite heavy.

For more information on how to care for your pool, view our literature page.