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Thursday, August 30, 2012

Vinyl Liners: mil or gauge? Buyer Beware

Vinyl Liners 20 mil VS 20 gauge:  Buyer Beware

We have always measured liner thickness in mil since I can remember for the past 45 years.  I remember my shock and confusion when a customer came in and asked "what gauge is your liner?" recently.  I had to do some research.  A distributor's representative where many liners are purchased by pool professionals told me they were the same.  I didn't buy it or I would have heard that before in my life.  I talked to a quality liner company, Loop Loc and their young representative Andres, and knew the answer.  They had done their homework with what was happening in our industry.  

What I found out is that mil is the exact measurement of .001 of an inch.  This is a standard measurement when measuring with a micrometer to determine thickness.  Gauge is what we usually measure the steel pool panels by.  Gauge does not have a predetermined set thickness.  Gauge means approximately close to but not exact.  The steel process of manufacture does not allow a consistent thickness, but close to.  Only iron metal products are measured in gauge.  Metals such as aluminum and copper are measured by ounce.   As you go up in gauge the thickness is less.  So a 20 gauge panel is about as thick as a sink and a 14 gauge panel will hold up to static pressure such as in a pool better.

So lately many will advertise the upgrade of going to a 27 mil liner for the same price as a 20 mil. Certain manufacturers are able to get a gauge liner and are not held to the exact measurement.  The savings for them can be made up over a whole roll of material.  However once stretched into a pool this would mean less than usual thickness and shorter lifespan but advertising allows 27 gauges at the same price.  Look at the table on the table below where actual measurements were made with a caliper and you will see it does make a difference when looking at the numbers.  This is why an experienced person can tell there is a difference between 20mil and 30 mil but has a hard time with telling from touch a 20 mil and a 27 gauge.
Bottom line is liners sold in gauge are not adhering to set principles and trying to deceive you.   

Saturday, April 14, 2012

Swimming Pool Robotic Cleaner Safety.

Robotic Cleaner Safety

     No doubt about it, robotic swimming pool cleaners are easy to use, do a great job of cleaning a dirty pool and are economical.  They save money in electrical costs, chemicals and conserve water; not to mention save us all time before jumping in the water.  But with any piece of equipment used around water we must follow safety precautions.  I highly recommend reading (yes, follow the directions) the owner’s manual to fully understand what is necessary for a safe swim.

1.) Leave the pool cleaner power supply in the cleaner caddy and a minimum of 5' from pool edge. It is highly recommended to use a caddy so that the cleaner power supply is in a stable area and to deter from pulling on the electrical cords. This can also help with preventing the power supply from being “accidently” kicked into the pool.

2.) Do not bury the cord, this way it cannot be hit by a shovel or machine doing yard work. Also the insulation is not meant to be underground. All underground connections should be in conduit but this would not allow for inspection for worn areas which is mandatory.

3.) Most cleaners use a grounded plug and should be plugged into a grounded GFCI receptacle.  There is a unit on the market (Zodiac S3) however that uses double insulation and therefore the 3 wire ground plug is not used on this unit. This unit avoids people trying to use a grounded plug in an ungrounded outlet. All metal parts are also double insulated from the electrical components.

4.) The homeowner, facility or unauthorized repair center should never try to repair a power supply or cord (either floating cord or power cord) and should never open the power supply. When sending a unit away for repair be sure to include the power supply.

5.) Do not use the unit with worn cables or damaged cables. These should be inspected before each use. Never remove or pull the unit by the cord, always use the handle on top of the unit.

6.) Never use an extension cord. Plug the power supply directly into the GFCI outlet at least 10' from pool.  The cleaner power supply should always be 5’ from the pool water edge.

7.) Many units have an automatic shut off in case of over -heating. Therefore; do not use the unit in water over 95 degrees.

8.) Do not have anyone or anything in the pool when the unit is being used as they could become entrapped. 

The safety issues that I see repeatedly have to do with electrical shock of ungrounded units and entrapment by the cord of a body, limb or the moving parts could entrap hair easily. The hair entrapment is a serious issue although I could not find anything to substantiate any cases so far – and I hope we don’t see any.  After working closely with the Pool & Spa Safety Act 2007 it just makes sense.

Wednesday, March 21, 2012

Exploding Filters

Exploding Filters

All types of swimming pool filters operate under pressure.  If air is trapped in the filter and not released the air will continue to compress while the filter is operating.  Small amounts of air can work its way out of the filter but large amounts will compress to a dangerous level.  When this occurs the filter may blow apart.  Also, if a retaining ring is not seated properly or if the tightening band fails this can happen.  Pressure build up from a filter not being cleaned can also build dangerous pressure.  During pollen season it is imperative to check the filter pressure often. Serious injury and death has occurred from an exploding filter.

Most filters will have an air release mechanism that needs to be opened when the system is turned off and also left open when starting the system until a steady stream of water comes out through the mechanism indicating that the air has been removed from the tank.  It is of the utmost importance to use this feature.

For filters that have a retaining band (clamping) with a bolt that tightens the band it is necessary to be sure the washer remains in place so that the bolt cannot slip and allow the top half of the tank to become a projectile when pressure builds within the unit.  This band and tightening mechanism also needs to be replaced if it has rusted or corroded as it could also be compromised.

With units that are connected with a tightening band or a “posi-lock” band (threaded like a mason- jar ring) it is very important to be sure that no dirt or debris is present in the area where the two halves are connected as this could also cause a failure.  Be sure that the halves are seated properly and fully seated when re-assembling.  Inspect the locking band for hairline cracks or ruptures on a regular basis.

In 2004 a recall was issued by the Consumer Protection Safety commission on some Sta-Rite and Aquatools brand filters.  These filters were manufactured from January 2003 – October 2003.  For more information see: 

When high pressure builds in some filters that are banded or bolted in the middle of the tank a leak may develop from that area due to the high pressure.  If this occurs turn the system off, wait a few minutes and carefully open the air relief valve to allow the pressure to escape.  After the pressure has been let out of the system, start the system up and allow a steady stream of water to escape from the air relief valve before closing it.  Backwash or clean the system as that can cause building pressure as well.

Again, regular inspections can prevent this dangerous situation.

Thursday, March 15, 2012

Vinyl Liner Mold - Black Bottom Stain

Vinyl Liner Mold

A discoloration of a vinyl liner can occur from mold/fungus that may grow under the liner.  This has the appearance of a black stain on the vinyl liner inside the pool.  It us usually round over a large area and is only seen on the bottom and side walls of a vinyl liner where the liner comes in contact with the bottom areas of the pool.  This can occur on the bottoms of above ground pools as well.

It does not brush off and may lighten in appearance after “shocking” the pool or periods of high chlorine residual.  Shocking and use of a copper based algaecide may kill the substance on the swimming side of the vinyl.  Although the mold can be lightened from water chemistry there is no way to treat the source of it on the outside of the vinyl from within the pool.  The mold can only be eradicated when the liner is removed and the ground is sprayed with a sodium hypochlorite solution of 5-10%.  The chlorine solution can be applied with a pressure type garden sprayer.  The solution must dry before re-installing the liner.  There are specific fungus products available on the market as well.

Another indication that vinyl mold/fungus is causing the discoloration is that the welded doubled seams of the liners do not show any discoloration as they are too thick for the mold to grow through.  The heat welding process also inhibits the mold/fungus from growing all the way through the seam.

This mold/fungus thrives in moist ground conditions.   Areas with high water tables or areas that have experienced flooding can be prone to this occurring.  Infected sand that is used for the base of the pool can also contain this mold/fungus.  Water tables can change over time and with environmental conditions and cause mold/fungus to grow when there may not have been a problem before. 

The plasticizers and lubricants used to make the liners are ingested as food for these micro-organisms and allow it to thrive.  The consumption of the plasticizers which make vinyl pliable comprises the liner integrity.  It is common to see this occur in one season.

The liner can be compromised as the pigment of the liner may be removed during the process of the mold growing through it.  This reaction happens when the bond of the ink and the vinyl is weakened and the ink rubs off.  Many liners are manufactured with a biocide/fungicide but it can be overpowered with heavy infection of the mold.

To avoid liner mold/fungus always be sure that the pool base is constructed with clean sand that is free of organic matter.  Be sure the liner you purchase contains a biocide or fungicide.

Chlorine levels of 5ppm usually will “fade” the mold on the inside of the liner.  Over time these areas may look bleached as if someone improperly added chemicals to the pool. 

Polyethylene sheeting can be laid down to act as a barrier between the vinyl and the ground as the mold/fungus cannot penetrate the polyethylene.  However, if water tables rise the sheeting can “float” with the liner and bundle up when the water level retreats.  A ground sealant or other chemicals can be applied but may get diluted by ground water.

Monday, March 5, 2012

Alternative Media for Sand Filters

Alternative Filter Media for Sand Filters

     Zeolite and Glass media were introduced to the swimming pool industry years ago.  At that time little was known about these types of media use in pools although they had been used in other industries for water filtration.  We now know much more and can make an educated decision if either of these are a choice we want to consider in our pools filtration system.

     The removal of particles during filtration and the efficiency of the media are very important.  With all of us attempting to be water conservative and energy efficient it is time to again look at these alternatives.

     A media that has steadily gained customers is Zeolite.  Zeolites can be natural or synthesized.   Zeolite is a honey combed shaped structure with a surface area 100 times greater than sand.  With the increase in surface area the filter is capable of collecting more dirt in a shorter period of filtration time which enables a decrease in how long you need to run your filter.  

     Zeolite will filter out particles down to 2 – 5 microns which is comparable to diatomaceous earth filters.  This increase of efficiency also increases removal of wastes, algae and gives superior water clarity without the expense of purchasing a new DE type filter.  Due to its low micron removable there is no need to use a clarifier while using Zeolite.

    Zeolite has the ability to absorb ammonium compounds that are created by swimmer waste.  Traditional sand filters do not have this ability.  By removing the ammonia compounds there is less frequency with having to “shock” the pool, eliminates red burning eyes by reducing the chloramines in the water.  This saves on the amount of chemicals you must add to the pool and saves money.

     Less dense in bulk weight than silica sand, Zeolite is used at the rate of half that of sand.  For every 50lbs. of sand you would use 25lbs. – 30lbs. of Zeolite.  It has the same life expectancy as sand which is 7 – 15 years.  You can “refresh” the Zeolite by soaking the media while in the filter in a 10% salt solution overnight.   This process is recommended every 2 years.  This still needs to be done with a “salt” type pool as the normal pool concentration is not high enough to properly refresh the Zeolite.

     There is an increase of 2 times the duration between backwashing over sand media filters.  Also the time to backwash the filter is cut by half.  This saves water and also the chemicals that have been used to treat the water.  When it is time to change the Zeolite media you can safely recycle it into the soil as it is an excellent soil additive or dispose of as a non hazardous waste unlike DE.   There is no hazardous dust to be inhaled with Zeolite as there is with diatomaceous earth. 

     On the initial addition of Zeolite there is a need to backwash 3 times with a short period of time between the backwashes to allow the Zeolite to settle.  This does waste some water but the benefits later outweigh this drawback.

     Another type of sand media replacement is crushed glass.  Although available in the states for some time it is more prevalent in Europe.  A study done for CWC which is a non-profit organization that provides recycling marketing services to business and government has documented that using glass media improves water clarity by 25% over sand media, increased the backwash efficiency by 23% and 20% less media was needed over sand media.

     With the increase of water clarity the filter run times can be decreased to achieve the same clarity of water.  The amount of time necessary to backwash the filter was decreased saving chemical treated and heated water.  Both of these save energy costs as well. 

     The glass particles used have the shape required to be able to remove particulates but are smoother than sand so that it is less likely to support algae growth.   The surface of the glass is negatively charged and attracts iron and manganese to it.  There is no silica hazard as with sand as well.  It works well with “salt water pools”.   It lasts 3 times longer than sand media with a 5 year minimum life.

     Glass media is not as readily available as Zeolite or silica sand at this time.  In discussion with distributors of this product there has been some objection by consumers to use this as the thought of glass entering the pool through a broken filter lateral would not be desirable.  Hopefully we can gather more information on this product and actual use in the future.

     Through the use of alternative filter media we can increase the clarity of our swimming pool water making them more inviting than ever without the use of more chemicals.  We can also make them “green” by saving energy as well.  You can make your neighbors “green” with envy on your beautiful pool with little effort or money.

Resources used:

“Evaluation of Recycled Crushed Glass Sand Media For High- Rate Sand Filtration”

CWC  October 1998

Zeo : Natural Zeolite Products web page (

Friday, March 2, 2012

Get Horizontal!

Horizontal High Rate Filtration

     A common type of filtration for all swimming pools for the past 35 years has been a vertical high rate sand filter.  But now we have horizontal high rate sand filters available that can increase energy efficiency and supply the filtration that is needed.

     Vertical high rate filters are limited to lower flow rate capability (gallons per minute)  as the filter area is small and the flow rate per square foot for applications can only go to 20 gpm/sq. ft.  A large vertical filter tank that is commonly used only has about 7 sq. ft.  Our industry uses vertical high rate sand filters in tandem for large pool volumes or where higher turnover rates are required.  This also demands more plumbing and control which increases the resistance or total dynamic head of the system.  When we increase the TDH in a system we need more energy to achieve the required gallons per minute of flow.  Depending on the need, this can also require more space to install the system.

     Horizontal filter tanks increase the flow media area available dramatically.  It is common for these types of filters to have 27 sq. ft. of filter area. This enables a system to provide more gallon per minute flow and increase turnover time.  Many of these filters are NSF (National Sanitation Foundation) approved for flow rate per sq. ft. down to 5gpm /per sq. ft. instead of 20 gpm/per sq. ft.  At 20gpm a horizontal filter at 27 sq. ft. of filter area would allow 540 gallons per minute of filtration as opposed to 140 gallons per minute in a 7 sq. ft. area filter. They can be installed in tandem for large pools as well but would require less tanks, plumbing and controls which would lower our energy (pump) requirements as there is less resistance. (TDH)  Automatic backwashing controls can be installed on these filters.  

     Ease of use, better cleaning and lower costs to install and maintain without the compromise of water quality make this type of filter an excellent choice for aquatic facilities and other commercial pools.

Thursday, February 23, 2012

Decrease Flow, Decrease Energy, Increase Circulation And Still Be Green

     A pool is an item that can increase a person’s health, family time and enhance a backyard environment.  But when the expense of maintaining the pool is beyond affordable after the initial expense, the dream can turn into a nightmare.  While researching ways to make our pools safer from suction entrapment our industry found that slower flow is better for pool circulation and our pocketbooks.  Having a “green pool” has new meaning.

     Many people invest in a pool as a life-long dream.  They work hard and save their money in hopes of having a backyard vacation and family area.  Pools have become affordable for many and not just the very rich.  However they do require energy to provide filtration, circulation and disinfection.  Energy costs have increased since 1999 in the Southeast by 45.7% (U.S. Energy Information Administration). These rising energy costs and the imperative need to reduce our energy consumption has local governments issuing demands for energy reduction in all areas of building code.  We are also looking to reduce our household budget demands during this economic downturn.   

     The swimming pool industry with the technical advancement of energy efficient pumps has been able to decrease the cost of running a pool by 90% or more.  This can mean pennies a day.  In the eighties the advancement of Dual Speed pumps gave us the ability to decrease costs by 75% over single speed pumps that are run the same amount of time per day.  In the late nineties multi speed and variable speed pumps increased the savings even more.  This is a significant reduction in energy.  With more competitive production of these energy saving pumps and increase in energy costs the cost to the homeowners of the initial investment usually pays for the upgrade in months.   

     We use hydraulic calculations to know the resistance of the pool system, figure the turnover rate needed to properly maintain clarity and disinfection and size a pump to fit the swimming pool needs.  One size fits all is no longer the educated way to purchase pool equipment.

     A pump motor works on different rpm or revolutions per minute to turn the impellor which forces the water to flow.  Swimming pool single speed motors use 3450 rpm.  Dual speed motors drop to 1750 rpm and Variable speed can reduce to averages of 1350 to 1000 rpm.   We are reducing the flow of the water and reducing the energy needed.  It was found during technical trials in reducing flow of water for entrapment prevention (APSP/ANSI 7 2006) that we were using less energy as well as reducing velocity. 

     To move water slower in addition to reducing size and speed of a pump we can also look to our pool system and reduce the resistance to flow allowing for less energy to move the water.  We can deliver more water through larger plumbing and reducing the amount of elbows and high resistance fittings such as multi port valves.  This slower flow of water reduces the velocity and resistance of the water flow, reduces energy costs, but also is quieter, extends the life of the equipment, filters to smaller particles and better distribution of chemicals in the pool.  We can run the pumps longer increasing the pool circulation and decrease the amount of chemicals needed.

     When the speed is reduced from 3450 rpm to 1750 rpm (reduced by ½) we will get approximately ½ the amount of flow, and also have ¼ the amount of resistance (Total Dynamic Head in feet) which gives us 1/8 the electrical consumption.  This is called the Affinity Law (Steve Barnes Pentair Power Point Presentation Florida Pool Show 2011). If we double the run time to compensate for longer turnover, we get ¼ the amount of energy savings.   This equates to approximately 2.6 KW used for 16 hours of run time.  With a single speed pump this would be approximately 8.1 KW! 

    When we apply the same principle to reducing speed even lower we can go as low as 1.9 KW to 1.4 KW for lower rpm.  This is a substantial reduction in energy load.  At the lowest amount we are only using 1.4KW to filter on a 24 hour basis. 

     With energy savings possible as shown above, it is within our reach to have a luxury item and be energy efficient.  Spending a little more in initial cost is better than not being able to have a pool at all.  If we have a product that consumes large amounts of energy it could possibly be legislated out of existence.  A swimming pool being green is usually not a good idea but where energy costs are concerned it is the wave of the future.

Friday, February 17, 2012

An Old Swimming Pool Kid.:       Pool& Spa Safety Act Falls Short of Safety ...

An Old Swimming Pool Kid.: Pool& Spa Safety Act Falls Short of Safety
: Pool & Spa Safety Act Falls Short of Safety In 2002 young Virginia Graeme Baker, granddaughter of Secretary of State James Baker...

      Pool & Spa Safety Act Falls Short of Safety

In 2002 young Virginia Graeme Baker, granddaughter of Secretary of State James Baker was held underwater by suction in a spa and drowned. In NC at a homeowner’s association pool another young girl was eviscerated by a suction line back in 1993 but was making news currently with her attorney John Edwards. Nancy Baker and Safe Kids Worldwide worked tirelessly to get Congress to enact laws for pool and spa safety. Representative Debbie Wasserman of Florida got the bill signed by President Bush known as the Pool and Spa Safety Act 2007. There was no doubt that even one accident is too many and a change needed to be made. Our industry was to learn so much more about hydraulics and entrapment. This newfound knowledge has caused many professionals to have issues and wonder why common sense and proven scientific studies have been ignored.

First the Consumer Protection Safety Commission studied from February 1985 to August 2002 how entrapment events occurred and how many resulted in death. We learned that of the recorded hair and limb entrapment events that 54% resulted in death. Body entrapment events accounted for 17% of deaths and of the 5 evisceration events that no death occurred. Most of these occurred in residential pools and not commercial. However the pool safety act was not retroactive to existing residential pools, only commercial pools. Many homeowners were led to believe that it was not important to them. Unfortunately residential pool owners have not seen the statistics nor has there been an aggressive campaign to educate them.

With technical research the adoption of dual main drains became required if main drains were being installed. No main drains were allowed as part of the ANSI /APSP 7 standard that was adopted by the Pool and Safety act also. The use of dual main drains was to slow the velocity down through the pipe so if one was covered and three feet away from each other so they both could not be blocked, that a strong enough suction would not occur to hold a body down or eviscerate. What Ms. Wasserman really did was double the chances for entrapment by limb and hair which had the highest percentage of deaths and injury of all types of entrapment. By doubling the occurrence of a missing or broken drain cover the new law succeeded to double our chances of death. This seems even more obnoxious as main drains are not needed at all for good circulation, cleaning or draining of any pool.

However we did learn that older drain covers are suspect to UV damage and now carry a date on them to be replaced. Design of main drain covers have been designed to hopefully mitigate mechanical and hair entrapment. It is very hard to see a main drain cover in the bottom of a deep pool or with any water movement.

We also have learned that if a cover is missing or broken regardless of flow that entrapment can occur. Human error cannot be legislated away.

The Pool and Spa Safety Act again failed in regards to suction entrapment. The allowance of a suction vacuum release system (SVRS) was heavily lobbied by the manufacturer of the device. This piece of equipment when in proper working order will shut off a pump within 3 seconds of low water flow and release the suction. However, even at the now required lower maximum velocity of water through the pipe at 3 feet per second for a single main drain the math shows that if blocked, nine feet of something could be sucked up the pipe within three seconds. That is still not acceptable and does not prevent evisceration. What is also not acceptable is the "water hammer"effect that could prevent the SVRS from cutting off power to the pump.

Much of the technical research done to prove the technical merits of ANSI/ APSP 7 standard has also created a better understanding of hydraulics which has led to energy efficiency and made our industry very aware of what we didn’t know. It has also increased awareness with code officials. The safety act was enforced before any training was available to the code officials or the public. Many pools were not opened due to costly repairs or not inspected properly many times. Few states have aligned their required codes which have put them in direct conflict with the federal act.

The most important change in legislation was not made as this bill was rushed through Congress before all the scientific studies could be concluded and expressed. Media attention on swimming pool safety was still high. It is now our responsibility to be sure the pools we maintain, install, or our family and friends swim in is safe. The only safe pool from entrapment has no main drain. It’s just that simple.

Tuesday, February 14, 2012

How Re$i$tant to Flow is Your Pool?

Total Dynamic Head and Why It’$ Important

     Total Dynamic Head is the resistance that your pool water has to overcome to circulate and move within the pool hydraulic system.  The flow of the water (hydraulics) is dependent on how easily it can move through the pipes, equipment, and pool fittings. 

     In our pool system we have a suction side and a return or pressure side.  We can take gauge readings to determine what each is on our pool.  But to calculate the entire system we must convert the suction and return readings to a common unit of measurement.  We use the measurement of “feet of head” for this purpose.  The pumps we use have charts supplied to us that show the “pump curve” or what flow the pump is capable of producing given a certain “feet of head” or “total dynamic head in feet” or with the resistance and friction loss.

     We measure the suction side friction loss of our system in inches of mercury (Hg).   We measure our return side in pressure per square inch (psi).  To find common value for our measurements we look at the air pressure that surrounds us.  When they have a common value of measurement we can add them together to get a total.

       If we take pressure gauge readings 10 feet into a tank of water we will find 4.33 psi (pounds per square inch) is the pressure of the atmosphere pushing down on water.  So using math we can determine that for every 1psi there is 2.31 feet of head (10 divided by 4.33 =2.31).  When we take a pressure reading on a pool system we multiply that number by 2.31 to give us a measurement in feet of head.

     Vacuum pressure is calculated in inches of mercury.  At sea level there is 14.7 pounds per square inch pressing down on us by the atmosphere.  If we use a vacuum pump you will see that the atmosphere pushing down on mercury will push it up into a tube 30 inches and no higher.  If we do the same with a vacuum pump and water in a closed tube it will rise 33.9 feet and no higher.  Therefore if we divide the water (which is in feet) by the mercury reading of 30 inches we conclude that we have 1.13 in feet of head.  We use the 1.13 feet of head multiplied by the vacuum reading in inches to have a measurement in feet of head.

     Now that we have our vacuum and suction readings in feet of head we can add them together to determine the Total Dynamic Head of the system or the total resistance we must overcome.

     So, why is this important?  This is important because we can determine how much water flow we have if we know what pump we are using.  We can determine if we are getting the turnovers we need to keep our water clean and disinfected.  We know if we have enough flow of water so that our equipment will work properly.  We can also determine if we are producing more flow than what we need.  If we are producing more flow than our system will allow than we have more resistance in our system and a higher total dynamic head than what is required. 

     The lower total dynamic head we have the less our pump and motor need to work.  The less our pump and motor need to overcome the resistance the less energy will be required.  The less energy that is required the less we pay for energy. 

     Many states have a new Energy Code that will require calculations to show the minimum pump size needed for your pool system.  The days of thinking that the bigger the better are now gone.  Energy efficiency is rewarded on some states with rebates on certain qualified equipment.  Wattage per gallon is especially helpful to customers who want to have a pool that is cost efficient after installation.

Monday, February 6, 2012

Do The Math Or Fail

Do You Know How Many Gallons Are In Your Recipe?

     The above is a question I find myself asking customers in our store many times a day.  When they answer that they do not know, I find these questions running through my mind:

1.)  How do you know how much chemicals to add to your pool?

2.)  How do you know how many hours a day to run your pool pump?

3.)  Do you know if you are spending more than you should on energy and chemicals?

 Likewise, the reason I am asking them in the first place how many gallons (or the size of their pool) is because they are asking me the following:

1.)  Why is my motor running hot?

2.)  I need to replace my pump what size do I need?

3.)  I want better flow (they mean pressure usually which should not be confused with flow), can I increase the size of my pump?

4.)  I want a new filter but don’t need to replace my pump.  What size and type can I get?

5.)  How much chlorine or other chemical should I add to my pool?

Everything we do on a swimming pool or spa is dependent on calculations. The entire design of the pool starts with calculations to properly size the circulation system or heart of the pool.  This determines how many returns, suction inlets, lights, size of pipe, how much pipe and so on.

     The equipment of your pool is the center of activity for your pool circulation.  To get the water into your pool and back to the equipment in a manner that will keep your pool healthy is based on hydraulics.  We determine the gallons in the pool, determine what our turnover rate should be (how many times the water is filtered in a day), the flow rate in gallons per minute and then calculate the resistance to be able to determine the proper pump size and match it to the filter type in order to achieve this.

     Heaters, chlorine generators, and other equipment will not work correctly if the flow rate is less than the minimum required or over the maximum allowed. 

     Next we use the pool gallons and dosage directions to calculate chemical dosages so that we do not over dose or under dose the pool with chemicals. This will require calculations from the testing of the water and the amount needed to raise or to lower to adjust to accepted levels of given parameters.

     So many times we find in our service department that someone has purchased equipment that they put on a pool will not function simply because someone did not do the math to find the flow rate required.  Likewise adding chemicals without calculating how much is needed can be harmful and a waste of money if the results are not reached as expected.

Knowing your pool size and doing the calculations is like baking a cake with a recipe.  If you don’t have a recipe and are just guessing you never know if the cake will be edible or maybe it will be edible but just look really bad. 

Saturday, February 4, 2012

Removing Barriers So All Can Swim!

Many heros will be coming home soon.  Many of our heros gave a part of themselves for our freedom but it also took away some of their personal freedom to move about freely.  We all know how therapeutic water therapy can be for the disabled, the elderly and anyone with impaired movement.
The American Disabilities Act (ADA) has imposed rules regarding barrier removal for the disabled in regards to swimming pools specifically for primary and secondary access. There are five acceptable means of access.  This rule is interpreted by each state in addition to the Justice Department.  A state may have clauses in their building code which may be stricter than that of the Federal Department of Justice.  This is true in North Carolina so what may be read online regarding fees or memberships to use pools in determining exclusions may not be correct on a state level. 
             For pools over 300 linear feet, two means of access must be provided with at least one required primary access type.  For smaller pools it is required to have one primary type access.

The two primary means of access would include mechanical lift chairs and also sloped entries to pools including ramps.

A mechanical lift chair can be permanently installed or be portable.  It should be able to have controls so the person using the lift can use as well as someone outside the seat area.  Various models are available with arm rests, foot support and portable batteries.  Again check with your state code as some states will not allow a portable model.

 The sloped entry can be built in or be a removable type ramp.  Sloped entry is recommended if there are a large number of ambulatory users. The slope access must be thirty six inches wide (48 inches in NC, so check with your state building code) and slope twelve inches for every one foot in depth (1:12).  For every thirty feet in length there must be a landing of level area of sixty inches long.  Handrails and an aquatic mobile chair are required with slope or ramp entries.

The three secondary means of access consist of transfer walls, transfer systems and accessible pool stairs.  The two primary means of access also qualify as secondary means of access.

A transfer wall is a wall where someone can transfer themselves from a wheelchair onto a wall and then ease themselves into the pool.  There is a grab bar the width of the pool wall to help in transfer.  A transfer system is similar to a wall where the person transfers from a wheel chair to the top of the device and then down the device into the pool water.   A grab bar must be used on this system.

Accessible stairs offer support and rails for balance to enter the pool from a standing position and have rails.
The United States Access Board has provided a complete and very useful summary at:

The Association of Pool and Spa Professionals provides some Q&A facts, and  updated Q&A  linked by the highlighted words or  available at
The Dept. of Justice has provided an ADA 2010 Update on Accessibility as well.  
As this is a complaint driven compliance issue, please be sure to check with your insurance company and counsel for the best policy and action to take.  New construction must be compliant, and all existing pools must be compliant or  have a plan in place by March 12, 2012.  For further information please contact the Department of Justice at

Saturday, January 28, 2012

Better Control, Less Work, Less Worries

     With new advances in technology and research available in our industry, we are now able to automate our pool controls and ensure better water quality.  Automation of controls minimizes operator error and can adjust water chemistry to maximize our sanitation control.  This is especially helpful in a managed aquatic facility or large pool setting.

     Sanitation of the pool water is the most important task for a pool operator.  A trained pool operator also knows that just adding chlorine is not enough to accomplish the job of disinfection.  The operator must know what the demand on the sanitation is according to bather load, temperature, pH, and many environmental and chemical factors.  Up to now the operator used breakpoint chlorination calculations and a fair amount of guesswork based on the gallons and flow rate of the pool.  With the introduction of ORP control units (Oxidation -Reduction Potential) we are now able to measure with sensors the quality of the pool water.  Quality of pool water is a measurement to oxidize contaminants.  This is measured in millivolts which is the count of the electrical charge available by the chemical molecules. When you oxidize (oxidation) microbes and organic material you reduce (reduction) the contaminants in the water.   The level of measurement is the potential the water has to be able to oxidize and reduce contamination.

     If we are constantly monitoring and adjusting the potential of the water then we are using dependable and accurate analysis and adjustments so that a build-up of contaminants such as chloramines does not occur.  The reduction of chloramines prevents swimmer discomfort and creates a pleasant swimming environment.  It also allows continuous control of bacteria, virus and parasites that can contribute to Recreational Water Illness. 

     As the effectiveness of sanitizer is dependent on pH then it is helpful to have a pH sensor in the ORP system.  As the pH rises then there is less oxygen associated with the sanitizer available to work.  The opposite would be that if the pH was low then there would be more oxidation.  However, this is not a measurement of sanitizer level and we need to establish a protocol of adjusting the pH first before adjusting the sanitizer. Automatic adjustment of pH by using a sensor and dispensing unit that is working simultaneously with the ORP system establishes the protocol of pH adjustment first then addition of oxidizer second if needed.

      We are only using the amount of sanitizer and acid needed to maintain a properly sanitized pool with ORP and pH automation.  There is no over dosing or under dosing of the pool chemicals by the operator, which can increase operating budgets.  Also, the pool operator does not have to manually make adjustments as often.  This allows a shorter exposure time to handling dangerous chemicals by the operator.

     We can be assured of quality control that is dependable and accurate, resulting in better sanitation that requires less work on the part of the pool operator.

Thursday, January 26, 2012

Why Use Ozone in Spas and Hot Tubs?

Simply put, Ozone is a natural oxidizer of wastes in water that could be harmful or cause unpleasant smells and cloudy water. The makeup of ozone is 3 Oxygen molecules that have a strong potential to change micro organisms such as germs and virus, into a state that is not harmful to bathers otherwise known as oxidation.

Air is drawn by one of two different types of ozonators (corona discharge or UV light) and becomes ozone. This is a process that duplicates the ozone being manufactured in our upper atmosphere by the sun. However we are controlling the process of ozone manufacture in our vessel. Without control of the ozone process there can be negative effects associated with too much ozone gas which is not healthy. However being controlled in process for our water and not combined with diesel fuel by products there is no comparison of danger as in air quaility issues.   Many times ozone for water quality management can get a bad reputation by being confused with the non controlled manufacture of ozone. As in any environment with humidity there should be adequate ventilation to prohibit water borne bacteria from being inhaled and in turn this ventilation will prohibit any exposure to a buildup of ozone gas as well.  Properly sizing the unit so that it does not over produce or under produce is also of importance when installing.

Ozone does not leave a residual in the water so it is used as a secondary oxidizer. It is recommended to use ozone in conjunction with chlorine or bromine (only in residential spas) so there is a continuous sanitizer level to prevent micro organism growth (disinfections). But it does not leave chloramines, bleach bathing suits, or damage the equipment. When ozone is used up it reverts back to oxygen which is natural as the air we breathe.

Other benefits to ozone are that you can reduce your chemical usage and there are not strong unpleasant odors to it. Because it helps keep the water cleaner you may be able to go longer between water changes as well.

Ozone is 3,000 times quicker than chlorine in killing micro organisms but yet is relatively safe. It is especially useful in killing Cryptosporidium, Giardia, Legionella and E Coli which account for the increase in RWI’s (Recreational Water Illness’s) our industry is seeing. It is not expensive and only needs to be replaced depending on the hour life. This may be 1 – 2 years but depends on the unit. If you have not had your hot tub checked recently to see if the ozonator is operational it is well worth the money for your safety to have this done by a professional.

With hot water bacteria breed quickly and the small amount of water per person ratio that is in the hot tub make it necessary to take extra precautions to maintain a safe, healthy environment for your enjoyment.

Tuesday, January 24, 2012

K.I.S.S. - Keep It Salt for Safety

You might think that manufacturing your own chlorine at home would be dangerous and unwise. You might think that adding chemicals to your pool is also dangerous and unhealthy. Both of those statements are false.

The manufacture of liquid bleach (chlorine) by using salt and a small current of electricity was started in the 1800’s. Now we can do this safely right at and in our pools and spas.

As chlorine works by oxidation which is the ability for a molecule to grab and burn oxygen we must use chemicals that promote this reaction to rid our pool/spa water of waste and bacteria. This would require the oxidizer used to be unstable so it can react quickly. We see this in fire situations where we are told not to open a door where there is a fire. Increased oxygen flow increases the ability to burn and flame. An oxidizer has the ability to burn, combust and explode depending on how fast it reacts with another chemical or product. This makes storage of oxidizers or shock products such as calcium hypochlorite and sodium hypochlorite dangerous to store in your home or business. You may be required to post a warning or informational card on your home, business or vehicle when transporting. We know that adding water TO calcium hypochlorite can cause an explosion. If a fireman comes to your home and business and sees a pool in the backyard they are wondering where you store your chemicals for they do not want to put a stream of water on a container of this strong oxidizer and create a worse situation.

The storage and handling of chlorine is also a problem that could be costly and dangerous. The fumes are very corrosive and if product is stored near lawnmowers, chain saws, chemical controllers, pumps and other usually stored items damage will occur in a short period of time. Unopened containers of chlorine can become brittle and crack allowing product to come in contact with grease or oils and ignite. Fumes are also dangerous to breathe and precautions for breathing and eyes must be taken when opening and dispensing.

Chlorine generators have no storage of dangerous products. The main product used is salt and there is no need to store any. Even if you did store salt it is not dangerous. It’s not expensive either.

With manufacturing the chlorine yourself the costs come down dramatically for sanitizer. The salt only needs to be replenished when the chloride (salt) level gets low due to splash out, leaks, backwash or dilution of the pool water. The salt stays in the pool during evaporation but can leave on swimmers and any way the water is physically removed. With rising costs of inorganic chlorine salt generation is economical and all of the initial costs can be recouped in a short period of time.

A disadvantage would be the initial cost of the unit and installation. The initial costs are much higher than an erosion feeder and it seems odd to be adding hundreds of pounds of heavy salt bags to your pool initially.

What is convenient is that to super oxidize the pool as needed you can just turn the production up on the unit or use a non-chlorine (MPS) type shock. There is no mixing of chemicals, fumes or work involved other than testing the water regularly to keep pH in correct levels.

It is still a chlorine pool so our water chemistry practice is still the same. Keep the chlorine level at 1.5 ppm to 3ppm and balance the water within parameters. However we do keep the total alkalinity at 80 ppm to 100 ppm to help us keep the pH at an acceptable level.

The mineral salts make the water feel soft and luxurious. It has the “ahhh” effect on people. Saline solutions are used for contacts so you know that the salt in the pool will not burn your eyes or delicate parts.

The pool does not taste like salt as it is not over 30,000 ppm such as seawater. But it does not have a steel taste either that can be found in pools with low pH and alkalinity levels. Pool water likes to be balanced and go to a pH of 8. However a pH of 8 is not acceptable in a chlorine pool as the weak chlorine (OCL) becomes more bountiful. Therefore we need to be sure as we do in all chlorine pools to keep the pH in range of 7.4 - 7.6.

Due to the electron process the cells can scale up so there is a need to acid wash the cell periodically.

As the pool is higher in total dissolved solids from the minerals of the salt it is more conductive to electron flow. This can cause some corrosion in a pool that is not properly bonded. However a inexpensive zinc anode can be placed in the skimmer basket to help counteract the process.

With producing chlorine on site the pool water keeps a steady residual as it is not depending on a feeder (human or automated). With less chances for a low sanitizer event then it is less likely that algae, biofilm or bacteria are allowed to grow. Evidence is suggesting that many oxidants can be formed within the water and further decrease biofilms. It is imperative to keep chemicals in the pool to combat bacteria, biofilm and other pathogens as they are more dangerous than the recommended chemicals.

There are three available models of chlorine generators: brine, in-line, and in-pool. I prefer the in-line model due to it’s convenience and available options. The in-line model is comprised of a cell with housing cord and power supply. Some models have a temperature probe that can increase and decrease the chlorine production automatically. Some models will read the actual salt reading in the pool where as some read an average of the past 30 days. It is important to know which type you have to avoid problems. Some in-line models will stop producing chlorine when the salt level is too high or the water temperature is above 96 degrees. This disadvantage does not have to be as long as you know what to expect.

The in-pool units can be a nuisance as kids may want to play with them. Brine tanks have to be monitored carefully as the by product of caustic soda has to either be drained or introduced into the pool.

As with all equipment there can be a failure and a resulting down time. It would be recommended to keep a back up method of sanitation for times as this.

Salt systems are not new to the pool industry. However they are more user friendly than ever before. You do not need to be a chemist but you need to have a good pool professional to check your water periodically or have a good understanding of water balance and recommendations for salt water pools.

Less work is a nice by product of the safety issues that present themselves when using a chlorine generated pool. The safer the pool and safer the water provides a safer environment bathers and community.