Aquatic Technology Pool & Spa, "Creating Water as Art."™

Aquatic Technology Pool & Spa, "Creating Water as Art."™
Pools as an art form - the way it should be!

Monday, June 18, 2012

So you want a Chlorine Free Pool? What you don't know may harm you!

 So you want a chlorine free pool?
You have heard so many bad things about chlorine and the environment...
how chlorine burns the eyes, causes itching skin and respiratory ailments...

You don't know, what you don't know
 The "negative effects" of chlorine are spread by Suzy's mom down the street, the lady at the beauty parlor and even your pediatrician...  all people who mean well, but do not understand the science of swimming pool water chemistry.

Over the years, this misinformation has compounded itself - to the point where businessmen have seized upon this "the sky is falling"mentality and introduced "chlorine free pools. 

Skin rashes, respiratory ailments & burning eyes

The facts are plain & simple: it is not the chlorine that causes bather discomfort. It is almost always from other water chemistry issues, and almost always due to the lack of proper chemical maintenance, testing, and the incorrect dosing of chemicals.

Among the most common complaints:
itchy skin (too little chlorine)
burning eyes (bad pH or too little chlorine - ammonia compounds)
green hair (excess copper)

All of these are attributed to other factors... but ignorant people immediately point their finger at the chlorine - because they "smell" what to them must be chlorine (but are actually chloramines).

People sense the strong "chlorine" smell around a commercial or indoor pool, or worse yet, a health club spa - and immediately assume that there is too much chlorine in the pool!

What you are really smelling is actually resulting from the LACK OF CHLORINE! You are smelling the chloramines off gassing.  Chloramines are ammonia compounds that are formed when chlorine combines with bather waste.  When there is a sufficient quantity of chlorine in the water chloramines cannot form.  When the bather load exceeds the quantity or feed rate of the chlorine, chloramines begin to form.

This is why you "smell chlorine" on your skin after swimming - but in reality, you are actually smelling your perspiration that has combined with the pool's chlorine that formed chloramines (ammonia compounds) on your skin!  A simple shower with soap & water will remove them.

As "Chlorine Free" as you'll ever get
The only real "new"technology is ozone (though it has been around for 30+ years). Done properly with sufficient contact time before re-entering the pool or spa - it has awesome effects on the water quality. Ozone works synergistically with the chlorine, taking over the business of oxidizing bather waste. Since ozone is a thousands times better oxidizer than halogens (such as chlorine, bromine, hydrogen peroxide), it takes over those responsibilities, allowing the halogens to work as sanitizers. The ozone will also kill biological pathogens & viruses, which ionizers will not.

I have personally been toying with ozone for over 18 years. I have 2 separate systems on my personal pool, plumbed into the filtration & vanishing edge systems. I have tweaked my own contact chambers & ozone destruct units to provide additional contact time & to be more effective.

Chlorine is Safe
THERE IS ABSOLUTELY NOTHING WRONG WITH USING LIQUID CHLORINE. To be politically correct & environmentally sensitive, we call it "bleach." Chlorine has been used as a pool sanitizer for over 100+ years. It is used to treat drinking water in almost every city in the world. It is used in almost every commercial swimming pool in the world to maintain clear, safe, and sanitary water.

People who do not understand how chlorine reacts with contaminants, heavy metals, and other chemicals, continue to spread myths about what chlorine does & does not do.
For example:
Chlorine does not turn hair green, but copper does (blue staining from copper + yellow (blonde) hair = green).
You cannot smell it around a pool, even at 3-5X the normal dosages, but you can smell chloramines (which are the result of too little chlorine).
At the correct levels (1-3 ppm) it does not burn the eyes, but incorrect pH or chloramines will!
When water containing chlorine must be dumped into a storm drain or sanitary sewer, the chlorine can be neutralized - heavy metals from ionizers cannot!

People who claim that they are "allergic" to chlorine, in almost every case are really experiencing reactions to the chloramines - which can cause itching & rashes.

Someone experiencing "allergic reactions to chlorine" (actually the ammonia compounds/chloramines), could additionally be experiencing an allergic reaction(s) to any of the countless biological contaminants that accumulate in a pool (or worse yet, a spa) when the chlorine levels drop too low:
  • Molluscipox virus.
  • Mycobacterium spp.
  • Verrucas.
  • Staphylococius aureus.
  • Cryptosporidium.
  • Leptospira interrogans.
  • Trichophyton spp.
  • E. Coli
  • Pseudonomas
  • Human pathogens: blood, saliva, feces, urine, perspiration, mucus
  • Epidmerophyton.
  • Acanthamoeba spp.
  • Human papilloma virus.
  • Legionella pneumophila
In asthmatics the inhalation of chloramines can aggravate asthmatic symptoms. But because chlormaines "smell like chlorine," patients report that the chlorine caused the asthmatic attack.  Their doctor, not knowing about chloramines, reinforces the myth, and the MYTH GROWS.

Additionally, alternative treatment manufacturer's and environmentalists point to the fact that chlorine is a carcinogen. Yes it is, but if the studies are investigated, one will note that the prolonged exposure, dosage quantities, and chemical concentrations of chlorine are way beyond what any normal human being will ever ingest over many lifetimes.

Again, it is the "chicken little syndrome" - "the sky is falling, the sky is falling..." Did you know that ingesting too much water, too quickly, can kill you??? Does that mean that we should outlaw the drinking of water??? Of course not, but in moderation, the exposure is more than acceptable.

The Secret is Even & Consistent Micro-Dosing
Depending on the scope of the project & chlorine needs, we use barrels to store liquid bleach that is delivered. Where large quantities are needed, say for example on Olympic sized swimming pools, we'll install an on-site electrolytic production. The electrolytic production also creates sodium hydroxide, which is collected for use in buffering the pH.

On site production doesn't always generate enough sodium hydroxide, so pH buffering is augmented with either C02 gas (it forms carbonic acid when injected to the pool water) or a 4:1 muriatic acid solution (4 parts water:1 part acid). At this ratio, the "boiling point" (vapor point) of the acid is reduced, so that caustic fumes are not generated. As an added precaution, the chlorine & acid barrel bung openings are kept sealed & barrels are vented to the outdoors with a 1/4" vent tube.

For water chemistry management and to provide an automatic & instantaneous responses to the demands for additional (or fewer) chemicals (due to 30 kids in the pool, a 100ºF+ heat spell, or a cool weather front), my preference is an automatic ORP/pH controller (CAT Controllers & Acutrol are my 2 brands of preference). It monitors the water, responding to the additional demands placed upon the pool by the environment or bathers, by controlling 2 fixed rate peristaltic pumps (Stenner is my brand of preference)- delivering chlorine & the 4:1 acid solution. 

A water chemistry monitoring system coupled with slightly over-sized ozone system, will provide you with as close to a chemical free pool as is humanly possible.

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool and Spa

Sunday, June 17, 2012

Infinity Edge Swimming Pool Spa Watershape Consulting Design Construction

Infinity Edge Swimming Pool, Spa and Watershape Consulting, Design and Construction is a specialty within the aquatic construction field.

Tom, Dick and Harry
Not every Tom, Dick and Harry can build one of these complex pools.  On many expansive estate development projects, the general contractor insists on controlling everything on the site. 

While they  are entitled to earn a living managing the overall project, certain specialty trades are best left to those with decades of experience.  A general contractor is a generalist - much like a family practitioner doctor.  But construction, like medicine, contains many specialties.  If you were sick, wouldn't you insist on the best specialist available?

So why leave the construction of a $250,000 - $1,000,000 to a general practitioner???

Specialized Training
Swimming Pool contractors, designers and consultants who specialize in complex infinity edge or hillside pools should have countless hours of training in geology, engineering (though they are not structural engineers), hydraulics, waterproofing, architectural and landscape design and construction methodologies.

Their decades of experience on various prior projects oftentimes involved a team of experts.  Soils engineers, structural engineers, world-class architects, landscape designers and interior designers often collaborate on complex projects.

The experiences gleaned from being a member of these world-class design teams, can oftentimes save a property owner tens of thousands of dollars.

Case Study:

The soils report on a recent project specified drilled caissons and a mat slab or grade beam foundation for the swimming pool, due to an overlaying layer of expansive clay soils.  The structural engineer was already in the process of designing an expensive foundation system, when I was retained to consult on the project.

Upon reviewing the soils report, I noted that the clay soils were only 4-6 feet deep.  Seeing that the pool varied in depth from 4-9 feet in depth, there was a good chance that most of the clay soil would be removed from the pool area merely through the process of excavating the swimming pool.

I raised this point and suggested that the complex and expensive foundation be abandoned.  Instead I suggested that any deeper pockets of clay soils be over excavated and back filled with a suitable material. It would be less expensive to over excavate the pool & to build it with vertical free-standing walls.  The areas around the completed pool could be back filled with other suitable excavation spoils from around the site.

The soils and structural said, "Ah, ha" when the lights suddenly went on.  Though I am not trained in either of their specialties, I have the experiences to draw upon.  Those experiences saved the client $50-60,000 - 10X my initial consulting fee!

Another Case Study:
On a hillside project, the top 4-5 feet of the site was overlaid with organic material and lose soils that could not support a pool.  The existing pool was cracked in 5-6 places and was rotating out of level.  A geotechnical investigation revealed that this top layer of material was actually sliding down the hillside.

The soils engineer and structural engineer both initially recommended a drilled caissons and gradebeam foundation.  Having worked on prior projects with similar conditions, I suggested that they explore a deepened step foundation.  Again, the hillside could be over excavated, removing all of the incompetent material.

The hillside would then be "benched," like a series of large steps, though with a slight backwards slant.  The downhill wall of the pool would be constructed on a trenched foundation.  The void behind the wall would be filled with an engineered fill, consisting of a cement slurry.  This engineered fill would have a bearing capacity over 100,000 times the minimum required to support the pool.  The installation of the slurry would be faster and less expensive than importing and compacting soil in 2-4 inch lifts.

Again, the client would have realized a savings of $60-80,000 on the foundation design alone!

Experience has Value
This prior experience can only benefit the client.  It brings a sense of reason to the engineers, balanced by the logic of the "person who has to build it."  Efficiency and economy are not sacrificed for quality.  Rather, unexplored viable options are presented that serve the project needs and benefit the client's budget.

The Long Haul
Yes, though I work on a "cost plus" basis, saving the client money means that I make less profit on a job.  However, this newly found money might allow the client to upgrade the finish materials or include design elements that were previously deleted from the project.

Being able to demonstrate to a client that I am willing to forgo a quick profit, to gain their long term trust, is what it my business all about.  Oftentimes as a result, I find that they will broaden my scope of work, refer me to their friends and include me in future projects.

Now, that's really the BIG PICTURE!

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool and Spa

Sunday, June 3, 2012

How does a Vanishing Infinity Negative or Knife Edge Pool Work?

How does a Vanishing Infinity Negative or Knife Edge Swimming Pool Work?

Knife, Infinity or Vanishing Edge Pools do not require a water over water or horizon view.  In fact some of the most remarkable edge pools are set in flat yards with views into woods or lush foliage.  The generic term for a pool that overflows one or more sides is a "water in transit" pool.

Edge Definitions

Infinity, negative, disappearing and vanishing edge pool are all the same.  The phrases are used interchangeably.  These pools typically have one side slightly lower that the others, over which water flows.

Knife edge pools are usually built on flat lots (though I have done combinations of knife edges and vanishing edges).  Knife edge pools appear to be normal pools with the water level operating almost even with the top of the coping or deck.  There is a diagonal slot in the face of the pool, into which the water overflows.  These are by far the most complex of the styles to master.

Slot overflows pools are pools that look as though someone left the fill water on, and the water has flowed up and onto the deck.  A narrow slot in the deck collects this water.

A gutter overflow pool, is a pool where the water flows over a rim and into a gutter.  The gutter can be in the face of the pool (inside the pool and below the deck - as in an competition pool.  Or the gutter can be set into the deck.  The pool is technically a perimeter gutter overflow pool.

A flooded deck pool is any pool where the water flows over the walls of the pool and onto the deck.  This can be a perimeter slot or gutter pool.

Perimeter overflow pools is a generic term that describes water flowing over the perimeter of the pool.  The edge details can be vanishing edges, knife edges, flooded decks, slot or gutter overflows.

Water in Transit

The key to making any of these pools operate correctly is to understand the hydraulics involved.  Each technique requires a different rate of flow.  If the techniques are combined, one cannot simply provide for the greatest flow rate required - it will flood or overflow the details that require less flow.

Every one of these pools requires that some water be stored outside of the main pool.  This can be an attached basin, a remote tank or a combination of the two.  The holding tanks must also be able to have the capacity to store water displaced by swimmers, wind and weather.

Remote holding tanks require an even greater understanding of hydraulics.  The water flows from the primary pool to these tanks via gravity.  The slope and diameter of the gravity drain line dictates the flow capacity of these lines - to a point.

Basics of Operation

Water from the holding tank is pumped to the primary pool.  The water over flows the edge(s) and drains back to the holding tank.  There must be enough water in the holding tank to fill all of the lines, raise the level of the pool to flood the edges, and fill the gravity drain lines back to the storage tank.  The most common mistakes are undersized holding tanks and plumbing lines.

Having a keen grasp of the hydraulic requirements of the various edge details is paramount when designing or constructing such pools.  Gone are the 1.5 and 2" plumbing that most pool builders are accustom to.

A failure on one of these pools can be an expensive repair - something that most swimming pool builders cannot afford to repair out of their pocket.  That leaves the property owner footing the repair bill!

You only pay for quality once!

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool and Spa

Friday, June 1, 2012

Swimming Pool Expert Witness discusses Colored Concrete Color Consistency

Colored Concrete - Color Matching and Consistency

Placing concrete is both a physical and chemical process.  While the physical placement and finishing of the concrete can be mechanically replicated, there are too many variables to accurately replicate the chemical process.  What does this mean???

Color Matching the Sample Chip

Matching the sample chip is not like matching paint chips.  There are just too many variables that are beyond the control of the contractor.  Color matching cannot be reasonably expected.  The concrete color manufacturers clearly state this in their promotional and technical materials.  Disclaimers abound...  yet, at least once a year, I am retained to represent a party involved in a dispute over the final color of decorative concrete.

Variables Beyond the Contractors Control

I am not going to get into the reason why each of the following items contributes to variations in color.  The factors that can effect a project may change during the day.  Transportation time may be short in the cool calm morning and longer in the hot breezy afternoon.  Each on their own can contribute to color variations:

  • temperature (moisture evaporation & set times)
  • direct sunlight
  • shade
  • wind
  • moisture content of concrete (mix water and moisture content of the ingredients, e.g. sand, rock, etc.)
  • ready-mix transportation time (traffic)
  • ready-mix batch size
  • revolutions of the mixer
  • batch of the raw materials (e.g. gray-ness of the raw cement powder)
  • liquid vs. powdered coloring agents
  • white vs. gray cement
  • admixes (water reducers, plasticizers, decorative aggregates, etc.)
  • minerals & chemicals in the mix water
  • pressure during troweling
  • curing compounds & methods utilized

Any concrete color sample, whether it be a factory supplied concrete sample or a printed color chip, should be a generalization of the color to be received.  It is impossible to exactly match the color sample.

It is guaranteed that the coloration of the finished concrete will vary once installed on the site.  The changing temperature during the day of concrete placement can effect the final color development.  Concrete that was in the direct sun & later in the shade or vice-versa, will develop different colors than concrete that remained entirely in the sun or shade.  Controlling the shade or sun is WAY BEYOND the control of the contractor.

Property owners, architects, landscape architects, general contractors or other specifiers need to understand, that though every attempt is made to remove the variables, there are variables beyond the contractor's control.

The only guarantee one should ever receive when signing a contract for the placement of colored concrete is:

a) It will harden,
b) it will crack
c) the color will vary from one area to another,
d) the color will not match the sample and
d) no one will steal it without making a lot of noise.

Damaging Effects of the Sun

The color of the concrete will lighten over time as it is exposed to UV radiation and normal wear.  Concrete that receives less sunlight (against the house, under arbors, north side of an object or structure, under potted plants or bbq) will retain it's original color longer. 

Though the outdoor umbrellas, interior carpets, fabrics and draperies in your home fade from the UV exposure, no one ever complains to the carpet installer about the sun damage.  Yet, concrete contractors are supposed to offer such guarantees???

As the concrete continues to cure & harden the color will lighten.  If you have any doubt about the final color you will receive, it is a safe bet to select a darker shade.  In a few months or years it will be exactly what you want.

Manage Expectations

Contractors need to manage the clients expectations.  They need to sit down with them & explain that there may be significant color variations throughout the project.  These are normal and to be expected.  Color variations on their own are not considered construction defects.  Even small mock-up samples will vary from the final colors.

The contractor needs to have the responsible party sign a disclaimer against matching any color samples - there are NO guarantees on color matching, color consistency or color variations.

Though there are millions of colored concrete projects in existence, a large number of them result in disagreements over the final color.  Disagreement can be avoided if the parties had reached that conclusion prior to the placement of the concrete.  And a signed disclaimer prevents anyone from ever saying, "no one ever told me" or "he never said that."

...just manage their expectations!

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool and Spa