Posts Tagged ‘pool’
Try WinterMoss even if you don’t have PoolNaturally water during the summer! After pool shut down, add the WinterMoss bag directly to your remaining pool water before covering for the season. Improves water quality over the winter and makes for an easier pool start up in the spring. For pools up to 50,000 gallons.
Purchase WinterMoss here
pH, Buffers, Total Alkalinity, Chlorine and PoolNaturally Plus
Everything You Wanted to Know And Were Afraid to Ask
By David R. Knighton, M.D. and Vance D. Fiegel, B.S.
Co-Founders of Creative Water Solutions, LLC
It’s all about hydrogen ions and water. Hydrogen, you remember, the most abundant molecule on earth, is in the upper right-hand corner of the periodic table of elements. It is just one proton and one electron. Two hydrogen molecules combine with one oxygen molecule to form water. The hydrogen ion (H+) in water has a positive charge; the mirror image chemical is the hydroxyl ion (OH-) that has a negative charge. These two ions are like a teeter-totter. When one is up, the other is down. An acid has a high concentration of hydrogen ions and a low concentration of hydroxyl ions. A base is just the opposite. Put an acid and a base together carefully because they react with vigor to make water and release a lot of energy.
To understand pH, buffers, total alkalinity, and chlorine in any body of water like a pool, spa, pond or drinking water, you have to understand hydrogen ions.
The term pH refers to the concentration of hydrogen ions in water. It is a logarithmic, not a linear, scale. Higher numbers refer to a decrease in the concentration of hydrogen ions while lower numbers reflect a higher concentration of hydrogen ions. That means that when the pH changes from 6 to 7, the actual change in the concentration of hydrogen ions is 10 fold lower, and a pH change from 6 to 8 is a 100 fold lower. Therefore, seemingly small changes in pH mean large changes in hydrogen ion concentration.
Buffers are molecules that can combine with and release hydrogen ions. Many different molecules can act as buffers. The most recognized buffer in the pool and spa industry is bicarbonate. Depending on the pH of a solution, it can either release hydrogen ions in the water, or combine with hydrogen ions in the water to remove them from the solution. Many other molecules also act as buffers. Many amino acids and proteins made from amino acids are buffers. Long chain sugar molecules can also act as buffers. Buffers stabilize the pH of a solution over a range of hydrogen ion concentrations and are most effective when the pH of the solution is near the pKa of the buffer. Buffering capacity is also dependent on the concentration of the buffer. Buffers perform best over different pH ranges. Pick the pH you want, add the right buffer, and the pH of the solution will stay stable over the range of that buffer. It is a chemical version of balance.
Bicarbonate is also one of the buffer systems in your blood. As the hydrogen ion concentration fluctuates in our blood, the bicarbonate and proteins in our blood combine with hydrogen ions if there are too many, or release hydrogen ions if there are too few, to keep the pH stable. It works well at a pH of 7.4 (that’s the pH of our blood when we are healthy) because our bodies can rapidly control the CO2 levels through a process called physiological buffering. It is not, however, an optimal buffer for recreational water systems. The bicarbonate buffer system has a pKa of 6.1, which is quite far from the operating pH of 7.2-7.6 typically seen in swimming pools. As stated above, buffers are most effective when the pH is close to the pKa. This would explain why controlling and maintaining a stable pH can be so difficult. Because the operating pH is more than one unit from the pKa of the buffer, the system is living on the edge of the ability of the bicarbonate buffer system to work effectively.
Why is a bicarbonate buffer system used in pools if there are better options? The first reason is that it is the buffer system that exists in tap water (and what is measured when we measure alkalinity). The second reason is that the chemicals used to control pH are relatively inexpensive. The third reason is that the use of a more appropriate buffer, with the right pKa (i.e. a phosphate buffer system), would require the use of additional chemicals, increasing cost and the complexity of the aquatic water system.
Total Alkalinity vs. Alkalinity
This confused us when we first started paying attention to the pool and spa water chemistry terminology. In chemistry, we learned that alkalinity is the absence of hydrogen ions resulting in a high pH. When we read the indicator strips and saw total alkalinity we thought we were measuring the hydroxyl ions in the water. A lot of hydroxyl ions mean a low concentration of hydrogen ions or an alkaline solution. These readings didn’t make sense, so we asked a dumb question and Tom Schaffer from US Aquatics, Inc. (he is a CPO instructor and has 30+ years industry experience) told us that total alkalinity, as viewed in the pool and spa industry, is a measure of bicarbonate buffer. Low total alkalinity reflects a low level of bicarbonate buffer in the water solution; it does not reflect the alkalinity (concentration of hydroxyl ions) of the solution.
Tom also told us about pH bounce when the bicarbonate level gets too low. This made sense to us once we knew what total alkalinity means. If there is too little buffer in a solution, adding hydrogen ions (acid) overwhelms the buffering capacity and will result in a meteoric fall in pH. This occurs if bicarbonate is the predominant buffer in the solution and the total alkalinity goes below 60. That’s why many state regulations require pool operators to keep total alkalinity above 60, so there is enough buffer to keep the pH stable.
If the total alkalinity is high, like in some source water, then there is so much bicarbonate that it is very difficult to get the pH to go down or to increase the number of free hydrogen ions in the solution. If you add enough hydrogen ions by adding acid, then a balance can be achieved to keep the pH stable. Add more bicarbonate buffer and you will have to add more acid to balance the solution. A high total alkalinity can also affect the use of CO2 to increase hydrogen ion concentration thus lowering the pH of the solution. To understand this effect we have to understand the chemistry of CO2, water, bicarbonate and acid. CO2 alone is not acidic. When CO2 is dissolved in water, a slow chemical reaction occurs to form carbonic acid. Carbonic acid then gives off hydrogen ions and forms bicarbonate. All these reactions are in equilibrium and occur at different rates. If the bicarbonate level in a pool is very high, then the reaction to form hydrogen ions from carbonic acid is driven in the opposite direction. As a result, adding more CO2 cannot increase hydrogen ion concentration and simply off gases from the pool water into the air without changing the water’s hydrogen ion concentration.
pH and Chlorine
When chlorine (or bromine) is added to the mix, the chemistry becomes more involved. We will talk about hypochlorous acid, not chlorine. Hypochlorous acid is the ion formed when chlorine is added to water. Hypochlorous acid is also the oxidative molecule that kills bacteria, algae and cryptosporidium. The ORP (oxidation reduction potential) probe measures the oxidative potential of the water. Since hypochlorous acid is the major oxidizer in pool water, the ORP is used to constantly monitor the pool water and to add chlorine when the ORP goes below a set level. Hypochlorous acid is very reactive, so it combines with a lot of other molecules to form new molecules. Hypochlorous acid changes when the pH goes above 7.6. It basically morphs into a form that doesn’t react anymore, so it doesn’t kill anything.
Remember, because the scale is logarithmic, that a change in pH from 7.3 to 7.6 results in one- half the concentration of hydrogen ions. This is a very large change. Hypochlorous acid works a lot better at pH 7.2 to 7.4. That’s why keeping the pH at this level reduces the amount of chlorine needed to maintain a desired free available chlorine level.
pH, total alkalinity, buffers and PoolNaturally Plus
PoolNaturally Plus contains the leaves of one species of Sphagnum moss. PoolNaturally Plus affects the pH, buffer and total alkalinity of the water it touches. If you test the water in a wetland bog that contains Sphagnum moss it will be acidic (high hydrogen ion concentration). Sphagnum moss leaves and therefore PoolNaturally Plus, have a cation exchange system that binds positive ions, like iron and calcium, and pumps hydrogen ions into the water causing the water to become acidic.
During testing in pools and spas, we also found that PoolNaturally Plus stabilized pH and lowered total alkalinity over time. What was interesting is that even with the lowered total alkalinity we found no pH bounce or pH instability at all. This prompted us to allow the total alkalinity to equilibrate and see what happened. To our surprise, and the pleasant surprise of the pool owners and operators, they didn’t need to add bicarbonate to elevate total alkalinity to prevent pH bounce. Using PoolNaturally Plus, we recommend keeping the pH between 7.2 and 7.4 and letting the total alkalinity equilibrate to a steady state over time. This results in a net decrease in the bicarbonate and acid needed to maintain stable water.
Using CO2 with PoolNaturally Plus works very well. Because the total alkalinity is low, there is a low concentration of bicarbonate in the water. This facilitates the conversion of CO2 to carbonic acid and then to hydrogen ions and bicarbonate.
We also documented a decrease in chlorine delivered to the pool needed to maintain a stable free available chlorine (hypochlorous acid) level. The oxidative state of the water also became stabilized as measured by ORP. The end result is stable water using less chemicals.
By Vance D. Fiegel, CWS Founder and Chief Scientific Officer
We have all walked into a swimming pool facility, health club, or small motel and immediately recognized that “chlorine” smell emanating from the pool. We have grown to accept the odor and the other side effects of chlorine disinfection as the price paid to have a sanitary swimming pool. The odor and many of these side effects are not actually caused by the chlorine, but are the by-products of chlorine disinfection. Chlorine and bromine are common aquatic system disinfectants and are very effective at killing bacteria. They, and their halogen brothers fluorine and iodine, are all effective sanitizers because they are strong oxidizers (oxidation is the way bacteria is killed). Halogens, like chlorine, are all one electron short of filling their outer electron shell. They are always looking for another compound from which to steal an electron (oxidize). However, their oxidative power is not limited to just attacking bacteria.
Disinfection by-products (DBP) are formed when chlorine oxidizes organic compounds. These organic compounds are found in bacteria and many are critical for the bacteria to live and thrive. However, a lot of organic compounds are naturally present in our water, and putting people into the water introduces even more of these materials (dead skin cells, sweat, urine, etc). When chlorine interacts and oxidizes these organic compounds, it results in a tremendous amount of newly created compounds…but, these now contain chlorine (DBP). We generally classify some of these as combined chlorine or chloramines. It has now been established that many of these DBP are toxic, and while most remain in the water, some are quite volatile and released from the water into the air (i.e. chloroform). These DBP are what we recognize as that “chlorine” smell.
In short, chlorine is going to cause a reaction with anything in its path, and some of these reactions are going be toxic. So, that funky “pool smell” isn’t the chlorine. It’s the dark side of chlorine’s work.
Research at Embro Corporation (Creative Water Solutions’ sister company) is actively investigating the process by which DBP are formed, and the levels of DBP in swimming pools and spas. Our early results have demonstrated that Sphagnum moss leads to a reduction in DBP levels within the first few months of use in a swimming pool. Pointing to the importance of this research are the increasing numbers of scientific articles documenting production of toxic DBP in aquatic systems. They illustrate increased health problems for those experiencing high exposure to these compounds, including competitive and avid recreational swimmers. Stay tuned to our newsletter and website for the newest results of our research in this area.
Creative Water Solutions has been recognized by Plymouth Magazine for having two must-try green products. The article features the city of Plymouth and the plethora of sustainable services, businesses and initiatives it has to offer. The six part series showcases the local green movement. Read more at Plymouth Magazine.
During the summer months, there’s nothing better for adults and kids alike than taking a dip in a nice, cool swimming pool, lake, or river. Summer is also when we head to the lake and rivers with our boats, jet skis, kayaks, etc.
Yet, as we know from recent events, water fun can swiftly become tragedy if some simple, basic safety rules aren’t observed. Make sure you and your family are water safe by following these safety policies:
BASIC WATER SAFETY
Learn to swim
The best thing anyone can do to stay safe in and around the water is to learn to swim. The American Red Cross has swimming courses for people of any age and swimming ability.
Learn CPR and insist that babysitters, grandparents, and others who care for your child know CPR. The American Red Cross and the Minnesota National Safety Council both offer CPR classes.
Never leave a child unobserved around water—any water, including pools, spas, bath tubs, etc. Adult eyes must be on children at all times when around water. The average child stays on the surface of the water for only 10 seconds and the drowning process can start after they are submerged within 20 seconds.
It takes as little as 2 inches of water and 2 minutes for a child to drown. Toilets and buckets of water can be deadly to toddlers, who are top-heavy and can fall over head first. If you have toddlers in your home, always keep the toilet seat down and never leave a bucket of water unattended.
Always swim with a buddy; never swim alone, even in your own pool.
Wear a lifejacket or PFD whenever possible, the Personal Floatation Device must be US Coastguard approved and fit properly.
Don’t swim if you’re under the influence of alcohol or other drugs.
Make sure the depths of your pool are clearly marked. Teach children and other inexperienced or non-swimmers to stay in the shallow end.
Post CPR instructions in the pool area.
If you have a cordless (not cell) phone, keep it with you at the pool. If there is any pool emergency, call 911 IMMEDIATELY; then attempt rescue efforts.
Always keep basic lifesaving equipment by the pool and know how to use it. Pole, rope, and personal flotation devices are recommended.
Enclose the pool completely with a self-locking, self-closing fence with vertical bars. Openings in the fence should be no more than four inches wide. The house should not be included as a part of the barrier.
Pool covers should always be completely removed prior to pool use.
Consider installing an alarm that will sound if anyone or anything falls in the pool. Remember: A child can drown in less than two minutes.
Never leave furniture near the fence that would enable a child to climb over the fence.
Keep toys away from the pool when it is not in use. Toys can attract young children into the pool.
If a child is missing, check the pool first. Go to the edge of the pool and scan the entire pool, bottom, and surface, as well as the surrounding pool area. Keep your pool water sparkling clean so if someone is on the bottom, they can be seen.
Make sure your pool deck is made of or treated with slip-resistant materials.
In public swimming pools, always swim in areas supervised by a lifeguard and read and obey all rules and posted signs.
LAKE & RIVER SAFETY
Children or inexperienced swimmers should ALWAYS wear a US Coast Guard-approved personal floatation device/life jacket when around the water.
Watch out for the dangerous “too’s” – too tired, too cold, too far from safety, too much sun, too much strenuous activity.
Set water safety rules for the whole family based on swimming abilities (for example, inexperienced swimmers should stay in water less than chest deep).
Be knowledgeable of the water environment you are in and its potential hazards, such as deep and shallow areas, currents, depth charges, obstructions and where the entry and exit points are located. The more informed you are, the less likely you are to be injured or killed.
Use a feet-first entry when entering the water.
If you are a new or returning PoolNaturally® user, here are our suggestions for a more natural pool opening:
Spring Start Up/Opening
Install the PoolNaturally® system at the beginning of the pool season for best results, but better late than never! Returning PoolNaturally users report much easier pool start up the following summer. Excellent opening results are seen even if users installed PoolNaturally as late as August of the last pool season.
Start with a fresh filter
Remove filter media (sand, DE) and replace with fresh media if you are just starting the PoolNaturally system. If you have a cartridge filter, for best results replace it or please ensure the cartridge is well cleaned. Why? If you are new to PoolNaturally, your pool has years of accumulation of biofilm and the filter will contain a large amount of it. The easiest way to get rid of much of it fast is to change out the media or replace the cartridge filter.
If you used PoolNaturally last season, be sure to backwash the sand filter after filling your pool with water. Place cleaned or new cartridge filters back in the system.
Less is more!
When starting/opening your pool, know what you are putting in it! If you used PoolNaturally last summer, don’t start by adding shock, algaecides and cyanuric acid. Expect that your pool will start up with a minimum amount of additives.
-Add chlorine to get desired free chlorine.
-Adjust pH, alkalinity, hardness , and CYA to recommended levels below:
- Free chlorine 1-2 ppm
- pH 7.2-7.6
- Alkalinity 40-120
- Hardness 200-300
- CYA *less than 20 ppm
-Once water has been balanced, add PoolNaturally® PoolRefills to PoolNaturally® contact chamber according to the dosage chart below. It is important that once there is enough water in your pool to start the pumps, get it balanced and add PoolRefills as soon as possible, to begin experiencing the conditioning effects of moss.
How Your Pool Will Change With PoolNaturally
Depending on the age and how much your pool is used, there could be a lot of material (including scale) that is shed from the pipes, pumps, heater, and pool surfaces – this is evidence that the PoolNaturally system is working! Use a pool vacuum to get rid of the larger particles that settle out in the pool and clean or backwash filters to get rid of the smaller particles.
Maintain 1-2 ppm of chlorine – you won’t need anything higher. With PoolNaturally, your pool is no longer precariously on the edge of ‘going bad.’ It will take less chlorine to maintain this 1-2 ppm free available chlorine, so turn down your automatic chlorinator or salt generator to the lowest settings.
Cover up –
covers prevent both water & chemical loss from evaporation
Reuse the water –
use drained pool/spa water to irrigate your lawn (just remember don’t add any chemicals 3 days prior to draining)
by going large scale (direct solar panels) or small scale (accent lights) the devices will pay off when it comes time to pay the electric bill
Make it recycled-
Thinking of revamping the backyard? Look into recycled products: cabinets, patio furniture, and fencing are just a few of the products you can get from recycled material. They are low maintenance and made to last for a while
Lower temperature, more saving -
by lowering the temperature of your spa 3 degrees while it not being used can save you 5-10% of your spa heating cost
Last week we talked about biofilm, the microscopic colony of bacteria that lives where water, bacteria and any surface meet. Scientists who study bacteria in the laboratory have known about biofilm for 10-15 years. It has taken that long for the laboratory bench research to impact our daily lives and biofilm impacts just about everything. Think about it: combine water, a surface and bacteria and you have instant biofilm.
Biofilm: A Slime City
A recent article in the July/August 2009 issue of Discover by Wendy Orent called “Slime City” talked about biofilm and its impact on medicine and implanted medical devices. She did a great job describing what is known about biofilm and how it causes serious diseases and problems in the body. View the article: http://discovermagazine.com/2009/jul-aug/17-slime-city-germs-talk-each-other-plan-attacks/?searchterm=Slime
The same biofilm that coats medical devices, your teeth, or an infected bone or wound covers every surface of your pool or spa. All disinfectants such as chlorine, bromine, ozone, cooper or silver are effective killers of bacteria that swim in the water. Unfortunately, that’s only 1-2% of the bacteria that populate a pool or spa. The rest are safely protected from the disinfectants by biofilm.
The colony in biofilm is static. It is alive just like a city. The bacteria move, send off microscopic streamers of biofilm containing bacteria to settle on other surfaces, send off microscopic balls of biofilm to roll along the surface to start a new colony, and provide a nursery for bacteria to multiply and replace those that die off.
A Slime City in your pool or spa?
You see the effects of the biofilm streamers when your spa forms foam on the surface of the water. Biofilm free water in a spa doesn’t foam. The air bubbles injected into the water from the jets come to the surface and pop. Biofilm in pools and spas cause the rings and scale on the pool sides. It also causes cloudy water.
Recently, the scientists at the Center for Biofilm Engineering at Montana State University (http://www.erc.montana.edu/) discovered that biofilm causes corrosion of metals. At the interface of the metal surface and the biofilm the pH is around 1 and there is a small electrical current produced by the bacteria. The combination can cause electrolysis of almost all metals.
Think of your spa or pool’s heater cores, motors, seals and metal fittings. The microscopic biofilm is slowly eating the metal causing mechanical failures that are costly to replace.
The take home message is that biofilm is a major contributor and cause of most problems in pools and spas. So, how do you get rid of it? Tune in next week for more.
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