As you can see in the above diagram water is drawn into the skimmers and suction inlets by the pool's pump. As the water passes through the skimmer, larger debris is caught by the skimmer basket. This protects the piping from becoming clogged should a large object get pulled in.  After the water passes through the skimmers it travels through underground pipes where it enters the pump. Usually there is another basket in the pump to insure further protection against damage from large objects. The pump uses an impeller to pull the water from the pool and push it through the filter.  As the water exits the pump it's then pushed into the filter.  Here the water is cleaned using one of a few methods which we'll discuss in detail later. After the filter has done it's job cleaning fine debris,  the water is pushed back into the swimming pool where it exits through the hydro jets. These jets serve an important role in pressurizing and directing the water to establish good circulation without any "dead spots" - areas of stagnant water. Keep in mind that all pools work on this same basic principle. Next we'll look at the individual components that make up the support system in detail.

At the heart of the system we have the pump.  Pumps come in different brands and sizes but they all accomplish the same basic task of re-circulating the water.  There seems to be a trend towards "bigger is better" when it comes to pump sizing but simply buying a larger pump can be a big mistake.  A few problems that can occur by using too large of a pump are:

• The filter is "overdriven" and since water is being pushed through it so quickly, much of the dirt passes through unfiltered.
• If the electrical wiring going to the pump isn't sufficient, the motor will overdraw the circuit. If there isn't enough power to run the motor it will fail prematurely.  More pump motors fail from bad electrical connections or wiring not rated to carry the required amperage than anything else.
• The customer is inclined to run the pump less because it costs more in electricity. This means the water is not circulating as often and the pool will use more chemicals as a result.

As you can see a properly sized pump and system to match is the wise choice.

Sand  - By far the most popular and common method of filtration is sand. Sand filters share two things in common: 1) When in the filtration mode, water always flows from top to bottom; 2) They all have some sort of lateral or under-drain with slots to hold back sand while allowing clean, filtered water to pass through.
 High-rate sand filters use a special filter sand, normally .45 to .55 mm (also known as pool grade #20 silica sand), because it has sharp edges that serve to separate particles, allowing filtration to take place. They operate on the basis of "depth" filtration; dirt is driven through the sand bed and trapped in the minute spaces between the particles of sand. Initially, a clean sand bed will remove larger particles, and then, as the bed starts to load up with dirt, it will remove finer particles.
Cleaning of the media, or sand, is accomplished through reversing the flow through the filter, to the "waste" line. This is known as backwashing.

Diatomaceous Earth - Technically speaking, earth filters are the finest because they're capable of removing smaller particles than either sand or cartridge designs. The downside of this benefit is increased maintenance and complexity.
Diatomaceous earth is a porous powder with microscopic openings, that, when magnified, look like tiny sponges. Clear water can pass through these openings, but particles, as small as one to three microns, are trapped during the first pass through the media.
All earth filters have internal elements that become coated with diatomaceous earth. It is this 'filter cake' that strains dirt, dust, algae and some forms of bacteria from the water.
Similar to sand filters, when an earth filter becomes dirty, it is cleaned either by backwashing, or regenerating and draining, the clogged D.E. to the 'waste' line. To restore filtration, a fresh 'charge' of D.E. is added to the filter.

Cartridge - Cartridge filters use a paper element which is similar to the oil filter in our car. When water passes through a cartridge filter, dirt is screened out at the surface of the cartridge element. When clean, the element will trap larger particles, with finer particles being filtered out as the pores of the element become clogged by the larger debris.
The cartridge element can be removed and cleaned by pressure washing inside and out with a garden hose.

All three filter design can produce sparkling clean water. Choosing one design over another really depends on your needs. If ease of use and low maintenance is a factor, sand is the best choice.  If the finest filtration available is desired, or, if anyone is extremely sensitive to pollen then D.E. is a better choice.  Cartridges fall in the middle of these two designs and their biggest advantage is size.  Cartridge filters are much smaller and lighter than D.E. or sand filters.

Sodium Hypochlorite - Essentially the same as laundry bleach, this type of chlorine is sold in liquid form at a concentration of 12 - 15%.  The biggest advantage of using liquid chlorine is that it disperses into the water immediately and works fast. While it may be used for regular chlorination, most people find it inconvenient because it can easily ruin the interior of your car or clothing (like bleach) if dripped or spilled.  Liquid chlorine is also un-stabilized so it dissipates rapidly in sunlight.  Unless you're willing to add liquid chlorine to the pool twice daily or have a chemical feed pump installed to administer it constantly as the pump is running, it's best suited for shocking the pool or spring cleanups.

Calcium Hypochlorite - Commonly known as "HTH" by Olin products, this type of chlorine is a mixture of calcium and chlorine. It is available in granules or small tablets and like liquid chlorine, calcium hypochlorite is un-stabilized.  Because it contains calcium in it's composition it will temporarily cloud that water and it will also raise the hardness.  If your calcium hardness is low then using this type of chlorine will help, however if your calcium hardness is ideal or too high you should not use calcium hypochlorite to sanitize the pool.

Sodium Dichlor - This is the first of our stabilized chlorines.  It is only sold in granular form and is an ideal choice for daily chlorination because it does not affect the hardness or pH of the water and is fairly strong with an available chlorine concentration of 56%.

Sodium Trichlor - This is extremely concentrated chlorine with an available chlorine concentration of 90%.  The biggest advantage of sodium trichlor is its ability to dissolve slowly over time.  It is sold in large tablets (hockey pucks) and can last for up to a week when dispensed in a chlorinator or floater.  While this is very convenient, there are some reasons not to use sodium trichlor exclusively. First, it's very acidic with a pH of around 3.0.  To counteract this extreme acidity you must add pH increaser to the pool regularly.  Also, because of its high cyanuric acid content it's possible to build up too much of this stabilizer in the water.  Sodium trichlor should not be mixed directly with other chlorines so if you have a chlorinator installed on your system, NEVER pour granular chlorine into the skimmers!  Exercise caution opening the lid of an automatic chlorinator filled with trichlor tablets because the fumes can be overwhelming.

Solid Covers With Water Bags - This type of cover is still the most common, although many customers are realizing the advantages and security of safety covers.  Conventional covers of this type need to be pumped off over the winter as rain water accumulates on them. You'll need a cover pump to perform this task, we strongly recommend the Little Giant Water Wizard with a 25' cord.  A short cord on your cover pump can be dangerous because there's  the possibility it will wind up submerged in the water as you move the pump around. Place the pump onto the cover where the most water has accumulated.  Attach a garden hose to the pump and extend it far from the pool to lower ground so the water being pumped off does not accumulate near the pool.  Plug in the pump and keep an eye on the water so it doesn't run "dry", this can damage the pump.  If an excessive amount of water has accumulated on the cover and you notice the pool water level is very low after starting to pump off the cover, ADD water to the pool as you're pumping. This will guard against damage to the liner from the water level being too low.  Once the water is removed from the cover, unplug the cover pump.  Models are sold with automatic float switches but they can easily tip over on this type of cover, defeating the mechanism which should shut the pump off.  You may find that the pump gets clogged with leaves and debris.  If this happens, clean the strainer on the pump and remove debris from the cover using a pool leaf rake (item sold specifically for removing leaves, it attaches to your vacuum pole). Also inspect the water bags periodically.  If you find some of the bags have leaked, replace them promptly. Do not put rocks on the cover or attempt to tie it down.  Rocks won't seal the cover well allowing wind to get underneath it thus lifting the cover and possibly pulling the rocks into your pool.  If this happens, severe damage to the liner can result. Tying the cover is another bad idea because it can rip.  The weight of water on the cover is unstoppable and the covers are not meant to be tied down.

Safety Covers, Solid - Pools fitted with these covers are virtually maintenance free.  The only two things you need to do are, keep the vents clean by brushing them with the algae brush. This will allow water to pass through them freely. Should the water level in the pool becomes so high that water is seeping up through the vents  you should lower it to an appropriate level using a submersible pump or siphon. If the cover is sagging excessively, have the springs re-tensioned as soon as possible.

Safety Covers, Mesh Designs - These covers offer the easiest winter maintenance off all designs, however the water underneath the cover may require more chemical treatments and perhaps even mid-winter additions of chemicals to keep the water from turning green in the event of warm weather.  Grades of mesh covers vary greatly, some designs block up to 95% of the sunlight from entering the pool. Quality covers such as these nearly eliminate algae growth over the winter months while still providing the low maintenance of a mesh design.

Tutorials

Below I've outlined some operational procedures for the most common types of pool equipment. With minor variations, this encompasses most systems installed on residential pools. Keep in mind there are many small variables such as arrangement of valves that need to be considered and you should familiarize yourself with your particular system. If you are unsure of your equipment's operation, don't hesitate to contact us, it may save a lot of grief or potential damage.

Sand Filter Operation

How it Works
Sand filters use special sand to remove dirt particles from the pool water. Filter sand is loaded into the filter tank and functions as a permanent dirt removing media. The pool water, which contains suspended dirt particles, is pumped through your piping system and is automatically directed by the filter's control valve. As the pool water is pumped through the filter sand, dirt particles are trapped by the sand bed, and filtered out. The cleaned pool water is returned back from the bottom of the filter tank, through the control valve and back to the pool through the piping system. This entire sequence is continuous and automatic providing total re circulation of the pool water.
After a period of time, the accumulated dirt in the filter causes a resistance to flow and the flow diminished. This means it is time to clean (backwash) the filter. With the control valve in the backwash position, the water flow is automatically reversed through the filter so that it is directed to the bottom of the tank, up through the sand, flushing the previously trapped dirt and debris out the waste line. Once the filter is backwashed of dirt, the control valve is manually re sequenced to rinse, and then filter to resume normal filtering.

1. Be sure correct amount of filter media is in tank and that all plumbing connections are secure.
2. With the pumped turned off, depress control valve handle, turning clockwise, rotate to BACKWASH position.
3. Make sure all suction and return lines are open.
4. Prime and start pump allowing the filter tank to fill with water. Once the water flow is steady out the waste line, run the pump for at least 2 minutes. This initial backwashing of the filter is necessary to establish a normal operating pressure for your system.
5. Turn pump off and set valve to RINSE position. Start pump and run for approximately one minute. Turn pump off again and set control valve to FILTER position, restart pump. Your filter is now operating in the normal filtering mode, cleaning the pool water.
6. Adjust pool suction and return valves to achieve desired flow and best circulation. Oftentimes it takes experimentation to see where the returns need to be pointed to result in the best circulation. Check system for leaks and tighten connections as necessary. In the event of a persistent leak contact a pool professional.
7. Note the initial pressure gauge reading now since your filter is clean. This number will vary from pool to pool, this doesn't matter as it's only a reference. As the filter removes dirt and impurities from the pool water, the accumulation in the filter will cause the pressure to rise. When the pressure gauge reading becomes 8 psi or higher than the initial "clean" pressure reading you previously noted, it's time to backwash the filter. See BACKWASH under filter control valve functions.

Filter Control Valve Functions
FILTER - Set valve to FILTER for normal filtering. Also used for regular vacuuming.
BACKWASH - For cleaning the filter. When filter pressure gauge rises 8 psi or higher than the above start-up (clean) pressure:
Stop the pump, set control valve to BACKWASH. Start pump and backwash until water in sight glass is clear. If you do not have a sight glass and cannot see the discharged water, usually 3-4 minutes is sufficient. Proceed to RINSE
RINSE - After backwashing, with pump off, set valve to RINSE. Start pump and run for approximately 1 minute. This ensures that all dirty water from backwashing is rinsed out of the filter to waste, preventing possible return into the pool. Stop pump, set valve to FILTER, and start pump for normal filtering.
WASTE - To bypass filter for draining or lowering water level. Also useful for vacuuming heavy debris which would otherwise clog the filter.
RECIRCULATE - On some systems this is called WHIRLPOOL. Water is re circulated, however, the filter is bypassed in the process.
CLOSED - Sometimes called TEST, this shuts off flow from the pump to the filter. DO NOT try to run your pump with the valve in this position.

D.E Filter Operation - Grid Style

How it Works
Grid style D.E. filters clean your water using a very fine powder called diatomaceous earth. In a grid system, this powder coats a series of fabric panels inside your filter forming a paste. This paste traps extremely fine dirt particles making it a superior method of filtration. Please note that operating a D.E. filter without earth can cause the fabric grids themselves to become dirty, possibly damaging the filter. Most modern filters of this type utilize a control valve, much like a sand filter, however, some older models may use a push/pull valve. Due to the many variations of this filter type, I will attempt to explain the most common configuration. It is important to refer to the decal on your filter or your owner's manual for capacities and other details of your particular filter.

Initial Start Up of Filter

1. Be sure filter is properly assembled. In the case of a spring start-up often the filter clamp has been removed to manually wash the filter. Also be certain the grid is inside the filter, failure to do this will create a situation where D.E. will enter the pool creating a cloudy mess.
2. With the pump turned off, depress control valve handle, turning clockwise, rotate to BACKWASH position.
3. Make sure all suction and return lines are open.
4. Prime and start pump allowing the filter tank to fill with water. Once the water flow is steady out the waste line, run the pump for at least 2 minutes.
5. Turn pump off and set valve to RINSE position. Start pump and run for approximately 1/2 minute. Turn pump off again and set control valve to back to the BACKWASH position, restart pump. Allow the filter to backwash once again until the water comes out clean. Repeating this procedure cycling from BACKWASH to RINSE a few times will get more old D.E. out of your filter better than just one cycle. You may do this as many times as necessary, ideally you will see clean water coming out during backwash once the filter is properly cleaned.
6. Now that we've cleaned the old D.E. out of our filter as effectively as possible short of disassembly, it's time to add new D.E. back into our system. Referring to the decal on the filter or your manual, establish the correct amount of D.E. for your system. If you cannot locate the manual and know the sq .ft. of your filter, 1lb of D.E. per 10 sq.ft of filter area is a general rule. Also note a 13oz coffee can holds 1/2 pound of D.E.. Using a 5 gallon bucket, create a suspension with the correct amount of D.E. and water by stirring the mixture with a piece of wood or other tool and place this by an operational skimmer.
7. With the control valve on FILTER and the pump running, slowly pour the D.E. and water mixture into the skimmer. Note if at this point you see D.E. returning back into the pool, something is either bypassing your filter or your filter may be damaged internally. If this should be the case, stop at this point and contact your pool professional. If this is not the case and you do not see D.E. entering the pool, continue to add the entire bucket. You may have to scoop up more water to suspend the D.E. as it has a tendency to settle to the bottom.
8. Once all the D.E. has been added, adjust the pool suction and return valves to achieve desired flow and best circulation. Oftentimes it takes experimentation to see where the returns need to be pointed to result in the best circulation. Check system for leaks and tighten connections as necessary. In the event of a persistent leak contact a pool professional.
9. Note the initial pressure gauge reading now since your filter is clean and coated with earth. This number will vary from pool to pool, this doesn't matter as it's only a reference. As the filter removes dirt and impurities from the pool water, the accumulation in the filter will cause the pressure to rise. When the pressure gauge reading becomes 8 psi or higher than the initial "clean" pressure reading you previously noted, it's time to backwash the filter. See BACKWASH under filter control valve functions.

Filter Control Valve Functions
FILTER - Set valve to FILTER for normal filtering. Also used for regular vacuuming.
BACKWASH - For cleaning the filter. When filter pressure gauge rises 8 psi or higher than the above start-up (clean) pressure:
Stop the pump, set control valve to BACKWASH. Start pump and backwash until water in sight glass is clear. If you do not have a sight glass and cannot see the discharged water, usually 3-4 minutes is sufficient. Proceed to RINSE
RINSE - After backwashing, with pump off, set valve to RINSE. Start pump and run for approximately 1 minute. This ensures that all dirty water from backwashing is rinsed out of the filter to waste, preventing possible return into the pool. After rinsing you may return the valve to BACKWASH and cycle through backwash/rinse a few times or until water runs totally clear on backwash. After backwashing is thorough, shut of pump, return valve to filter position and add diatomaceous earth as described in initial start up.
WASTE - To bypass filter for draining or lowering water level. Also useful for vacuuming heavy debris which would otherwise clog the filter.
RECIRCULATE - On some systems this is called WHIRLPOOL. Water is re circulated, however, the filter is bypassed in the process.
CLOSED - Sometimes called TEST, this shuts off flow from the pump to the filter. DO NOT try to run your pump with the valve in this position.

D.E. Filter Operation - Perflex Style

Perflex style filters are produced only by Hayward Pool Products. They are unique in operation from most filters because they do not have a control valve. In addition, they're not technically backwashed because no reversal of water flow occurs when cleaning them. Like a grid style filter, these filters clean the pool water by passing it through a pasty coating of D.E. but rather than using fabric sheets, they utilize long fabric covered plastic tubes often referred to as "fingers". One big advantage of this style filter is that when it becomes dirty you don't always have to clean it. This is known as regeneration and the process involved dislodging the D.E. from the fingers and then allow it to re coat them exposing new clean facets of the D.E. particles.

All of the procedures listed below assume you're starting with a clean properly assembled filter. If you are unsure of your filter's status, contact Bob's Pool Service and have them inspect it before attempting to run your system. Let's start with identifying the various parts of your filter, these will be referred to later in the operational procedures.

1. Starting with a clean filter, turn on the pump and open at least one skimmer.
2. Determine the correct amount of D.E. powder for your filter, usually there is a tag on the side of the filter that will contain this information. If you cannot locate the manual and know the sq .ft. of your filter, 1lb of D.E. per 10 sq.ft of filter area is a general rule. Also note a 13oz coffee can holds 1/2 pound of D.E.. Using a 5 gallon bucket, create a suspension with the correct amount of D.E. and water by stirring the mixture with a piece of wood or other tool and place this by an operational skimmer.
3. With the pump running, slowly pour the D.E. and water mixture into the skimmer. Note if at this point you see D.E. returning back into the pool, something is either bypassing your filter or your filter may be damaged internally. If this should be the case, stop at this point and contact your pool professional. If this is not the case and you do not see D.E. entering the pool, continue to add the entire bucket. You may have to scoop up more water to suspend the D.E. as it has a tendency to settle to the bottom.
4. Once all the D.E. has been added, adjust the pool suction and return valves to achieve desired flow and best circulation. Oftentimes it takes experimentation to see where the returns need to be pointed to result in the best circulation. Check system for leaks and tighten connections as necessary. In the event of a persistent leak contact a pool professional.
5. Note the initial pressure gauge reading now since your filter is clean and coated with earth. This number will vary from pool to pool, this doesn't matter as it's only a reference. As the filter removes dirt and impurities from the pool water, the accumulation in the filter will cause the pressure to rise. When the pressure gauge reading becomes 7-10 psi above the initial "clean" pressure reading you previously noted, it's time to regenerate your cycle.
   
   

Stop the pump. Move the bump handle down slowly, then up briskly. Repeat 3 times. Restart the pump and filtration should resume at near the original flow and pressure with a clean filter. After each regeneration, and until the filter is cleaned, there may be a slight increase in the starting pressure. This is a result of dirt accumulating within the filter and is completely normal. You may regenerate your filter as many times as you wish, however, eventually you will need to clean your filter.

Cleaning is recommended when the pressure gauge rises more than 10 psi in less than a 24 hour period. To clean, first stop the pump; then move the bump handled down slowly, then up briskly. Repeat 8 times. Open the vent valve (located on top of filter tank), open filter drain plug or valve (if you have a valve). and allow water and dirt to empty out completely. (Note: if the filter is installed below the pool water line, close the suction and outlet valves) You now have a clean filter, close the drain valve or re insert the drain plug. Start pump and refer to procedures listed above under "pre-coating".

One of the most common mistakes perflex owners make is attaching a long collapsible backwash hose to the filter's drain pipe. Understandably in certain situations D.E. discharge is not desirable where the filter is located, however, doing this prevents proper cleaning of the filter. In such cases we would recommend changing the filter to a true backwashable style system. In addition to normal cleaning, it will eventually become necessary to have your filter acid washed to break down mineral deposits that form on the flex tubes. This is best done by a professional such as Bob's Pool Service and requires working with strong chemicals such as hydrochloric acid.