Posts Tagged ‘PoolNaturally’
Sand Filtration: the GOOD, the BAD, and the UGLY
Anyone who owns, cares for, or cares about pools, spas or any kind of recreational water, knows that water filtration is an integral part of every water system. Using sand for filtration is commonly used on recreational and residential pools and large spas. Here are some of my observations, thoughts and concerns about sand filtration.
The Good
Sand is cheap, plentiful, and when it is a particle, it works well as a filter medium.
The Bad
Sand filters are usually filled, sealed and the sand is forgotten. The commonly held belief is that back washing the sand periodically, “fluffs it up” and returns the sand to a particle state where it can again work its magic as a particulate filter. Some sand filters have never been opened for 5-10 years to inspect the sand.
Back-washing the sand filter is costly. Water lost during back washing needs to be replaced, heated and treated. Ideally, the pool operators backwash often enough to keep the sand working as a filter, but do not needlessly back wash so water, heat, chemicals and time aren’t wasted.
The Ugly
Inspecting and analyzing the sand from pool sand filters in both residential and commercial pools has been enlightening, to say the least. At the bottom and sides of many filters we found sandstone. Actual sand in the process of forming sandstone. It wasn’t the gravel that is often put down underneath the sand, but sandstone. The sand in those filters was anywhere from 2-10 years old. The sand that wasn’t rock was sticky and foul. When we tested it in our laboratory, we found that it was full of biofilm.
The Hypothesis
We know that in an aqueous environment that contains bacteria, biofilm forms on every surface. To be effective, filters have enormous surface area whether they are made from sand, charcoal, paper, glass or diatomaceous earth. The particles become covered with biofilm over time. Biofilm is very sticky so the particles stick together. As time and pressure continue to pack the biofilm-coated particles together they eventually become rock. So what happens during backwashing? The water will take the path of least resistance. We observed in these filters that there were channels in the sand. We think that the water follows channels through the sand that have become established over time.
We know that backwashing will not remove biofilm. In fact there are very few things that will remove biofilm. Strong acid or base solutions work but they destroy the filter, pumps, valves etc. We have demonstrated that a flush used in spas removes 90% of laboratory created biofilm in one hour, and that many other solutions that claim to remove biofilm don’t.
Getting Better Results
We also have observed that sand in filters where the water is treated with PoolNaturally® Plus (the commercial version of the residential product PoolNaturally®) appears to remain as particles. We think this is why we needed to backwash filters with PoolNaturally Plus much less often than those with conventional water treatment.
By understanding the relationship between biofilm, filters and water we are aiming to create biofilm free aquatic systems that require less chemicals, maintenance, and unwanted side effects.
Swimming Pools and Asthma
During our test this last summer at the St. Paul, MN outdoor aquatic park we surveyed the swimmers twice a week. One of the most striking findings was that swimmers with asthma did not need to use their inhalers when swimming in the pools that were conditioned with PoolNaturally Plus. We then treated the indoor aquatic park in St. Paul and had similar results.
Able to Swim Again
In fact one lady wrote to me about her inability to swim indoors due to her asthma. She was a competitive swimmer in her younger years and had to stop swimming because of severe breathing problems from asthma caused by the air in the pool. She heard about the sphagnum moss treated pools and how people could swim without using their inhalers so she tried swimming again. She reported that she could do a full workout without breathing problems and thanked me for “giving her back her favorite sport”.
With a little research the relationship between recreational and home water, chlorine and asthma became clear.
The Chemical Reactions
Here is what happens when we use chlorine to sanitize water in a pool or in our municipal water supply. As it turns out chlorine is not the problem. A byproduct of chlorine and biological molecules that contain nitrogen is the formation chloramines. These chloramines come in many different forms such as mono, di, and trichloramines. One of these compounds, a molecule called trinitrochlorine, has been implicated in causing airway irritation.
Trinitrochlorine is a volatile molecule that is extremely irritating to tissues such as your eyes, skin and airways. Because the molecule is volatile, it rises to the surface of water and is easily inhaled. In fact, in a pool, the levels of trichloronitrate are highest in the air right on top of the water. So every time a swimmer takes a breath, they inhale an irritant that causes airway constriction called reactive airway disease. The smell we all associate with a chlorine pool is actually the smell of the multiple species of chloamines, not chlorine. The problem is that chlorine is so reactive, it immediately finds and combines with nitrogen containing compounds to create chloramines..
Correlation between Pools and Asthma
A recent study reported in the pediatric literature, showed that children who are repeatedly exposed to swimming pools have a significantly higher incidence of reactive airway disease or asthma, than those who aren’t exposed to pools.
In our research laboratory, we are currently studying why the pools treated with PoolNaturally Plus don’t cause this reactive airway response, skin irritation, or burning eyes and don’t smell. We know that for chlorine to become trichloronitrate you need chlorine, nitrogen containing biological molecules and a low pH. It could be that the amount of biofilm in the pool correlates with the amount of trichloronitrate because biofilm contains and produces huge amounts of nitrogen containing molecules and it creates a local microenvironment that has a very low pH. It could therefore be the “engine” that drives the formation of these toxic molecules. In the laboratory we know that the moss in PoolNaturally Plus inhibits the formation of biofilm and if our hypothesis is correct it could greatly reduce the formation of chlorine to trichloronitrate by removing the primary nitrogen source, the biofilm . We will find out with further research
Cyanuric Acid and Last Summer’s Journey
This last summer we added our Sphagnum moss pool product to the Highland Park Aquatic Center in St. Paul. We treated two pools. One was a 430,000 gallon Olympic pool and the other was a 22,500 gallon children’s activity pool. You can read about the results on our website.
One lesson we learned involved cyanuric acid, outdoor pools, and chlorine. The accepted dogma is that cyanuric acid is required for outdoor pools and spas to stabilize the chlorine against UV degradation. In fact, most granular or solid chlorine sold in stores is stabilized with cyanuric acid. Dichlor and Trichlor have cyanuric acid in the formula.
When cyanuric acid interferes with chlorine
We started to try and understand the chemistry and science of cyanuric acid because of its side effects. Cyanuric acid above a certain concentration (which is dependent on pH) inhibits chlorine’s (hypochlorous acid to be precise) ability to oxidize bacteria. Failure to oxidize means no killing.
We also found that cyanuric acid is denser than water so it sinks to the bottom of a body of water. Therefore, the level of cyanuric acid on the surface of the pool or spa is the lowest level in the pool and it increases from there to the bottom. It will be the highest in the deepest part of the pool.
We tested this at the Olympic-sized pool. We sampled water at the bottom, middle and top of the pool. The cyanuric acid was set for 40 ppm. At the surface the level was 30-40 ppm, in the middle it was 60-70 ppm and at the bottom it was 100 ppm. From the middle of the pool to the bottom hypochlorous acid was essentially ineffective.
The other fact about cyanuric is that it is nonvolatile. That means as you add more and more to your pool or spa the concentration continues to increase. The only way to decrease the concentration is to empty some water and replace it with fresh water without cyanuric acid so you dilute out the chemical. In places where the spa or pool is full all year long, the concentration of cyanuric acid can increase to the point where the pool has no effective chlorine. I think this is why most pools have algae outbreaks starting in the bottom of the pool. The high cyanuric acid levels inhibit hypochlorous acid so no killing of algae occurs.
The experiment
So, after we learned this, I decided to decrease the cyanuric acid level in the pools gradually to see if it is really needed. The pool engineers told me “if you do that there will be no free chlorine in this pool in the morning.” We agreed to decrease cyanuric acid by 10 ppm each week and monitor the results. The free chlorine levels never decreased and the combined chlorine remained at 0. We decreased the cyanuric acid to zero and never added any more for the rest of the summer. The levels slowly decreased to zero as makeup water diluted out the cyanuric acid. The children’s activity pool behaved exactly the same.
In another pool we treated we were able to manage the large pool all summer without any cyanuric acid and maintained free chlorine levels from 1-3 ppm with no combined chlorine all summer.
Water treated with moss doesn’t need cyanuric acid
The bottom line is that with moss treated water, cyanuric acid is not needed. The mechanism for this probably centers around biofilm. I don’t think that cyanuric acid prevents chlorine from UV degradation or the free chlorine levels would have decreased in the outdoor pools we treated. We know the moss inhibits biofilm formation in the laboratory and know that biofilm absorbs chlorine. We know that free chlorine levels skyrocket when moss is added to the pool and to maintain a level of 1-3 ppm free chlorine, the chlorine added to the pool decreases by over half. So a pool with moss doesn’t need cyanuric acid. That allows the chlorine added to the pool to remain active providing effective microbial control.
New York Times covers Successful St. Paul – CWS Summer Test
Great New York Times Article:
As its license plates proclaim, Minnesota is the Land of 10,000 Lakes.
Now a Minneapolis-area company says it has figured out the secret to the state’s famously crystalline watering holes: moss.
Specifically, species of sphagnum moss that the start-up, Creative Water Solutions, envisions will keep tens of thousands of swimming pools clean while drastically reducing the use of chlorine and other harsh chemicals.
Read the full article: Clean Pools, Less Chlorine … With Moss? (Green Inc. Blog – NYTimes.com)
CWS Wades into Commercial Pool and Spa Waters
My name is Allan Schwartz and I have been working in the pool and spa industry for the past five plus years. The majority of this time has been spent focused on the residential part of this channel with Creative Water Solutions.
Eau de Chlorine?
Late this April, I was out to dinner with some close friends, Michael and Suzie S. We were talking about working out at the Minneapolis Jewish Community Center where both of our families belong.
"Chlorine is my perfume" - this isn't how it has to be for swimmers!
Michael was talking about how much he enjoys swimming now that he can’t run anymore because of his failing knees. He goes multiple times per week. Suzie stated at that point that she can always tell the days he has been swimming because in spite of showering after his swim, he still smells like chlorine and she doesn’t like to be around him.
Michael then asked me “why don’t you talk to the JCC about using your PoolNaturally® system for their pools”. Michael reminded me about the positive feedback I have been telling him about from our residential pool and spa customers. As it turns out, my company had been talking about beginning to expand into the commercial pool and spa segment of this industry.
A Natural Partnership
The JCC was very interested and were an excellent candidate because they have six different types of water bodies. They have a men’s and women’s spa, an indoor and outdoor wading pool, as well as large indoor and outdoor pools. The JCC started in May with their men’s spa which was the most troublesome area. Then the outdoor wading and swimming pools were added. Almost immediately, the bathers were approaching the lifeguards to inquire about what they were doing differently with the water. The changes were dramatic. Becky, the lifeguard supervisor recently commented on how much more enjoyable the pool water is considering how much of their working day is spent in the water.
Jon S, the Certified Pool Operator and maintenance supervisor, told me that while he was originally very excited to try our PoolNaturally and SpaNaturally systems. If he hadn’t been so involved with the changes he wouldn’t have believed them. The results have exceeded his expectations. Ironically, because of mechanical issues with the indoor lap pool, it will be the last pool to go on our PoolNaturally system. Michael S, who suggested the whole idea, swims in the indoor pool and has been anxiously waiting to swim and not smell like he is using chlorine as an after shave.
Preliminary Results Announced By City of St. Paul and CWS
SAINT PAUL — Mayor Chris Coleman, Creative Water Solutions, LLC President and CEO David Knighton, MD, and Parks and Recreation Director Mike Hahm will unveil preliminary results of the nation’s first public-pool sphagnum moss-based water treatment system installation at 11a on August 17 at Highland Park Aquatic Center (see link for more about this pool). 
The pilot project was undertaken with the innovative Minnesota-based company, which has already demonstrated the moss-based system’s effectiveness in residential pools and spas (PoolNaturally and SpaNaturally, respectively).
“It’s a completely different pool! My eyes and the kids’ eyes didn’t get red, the water didn’t smell of chlorine and it was a lot softer feeling in general,” said 19-year-old Mary Schmidt, a regular weekly visitor to the pool as a summer nanny. “I love it!”
To see the full media release, please visit this link.
Thoughts on the Moon Landing and Biofilm
Where were you when the first human foot made an imprint on the moon 40 years ago?
I was in Ferkessedougou, Ivory Coast working at a mission station for the summer between my sophomore and junior year of college. I spent part of my time doing maintenance and the other helping with surgery. I remember listening to the short wave radio as we heard Voice of America describe the landing. It was night and there was a bright African full moon. After they landed I went outside and looked at the moon marveling at the advances in technology that allowed that human footprint on the lunar surface.
The next morning I excitedly told my co-worker, in my broken French, what happened the night before. He asked me “How long did it take them to get there?” “Three days was my answer.” He thought a while and then said, “The moon is as far away as Buoake.” Buoake is a three-day walk from the mission station.
His frame of reference was completely different than mine and in a way both were accurate.
A Different Understanding
That experience is very similar to what is happening in the understanding of how bacteria live in pools and spas. The old, accepted model says that bacteria like to swim and remain suspended in the water. We now know that 99% of bacteria in water swim to the nearest surface, attach themselves, and set up a microscopic colony that is protected by a layer of sticky protein and sugar molecules we call biofilm.
The biofilm protects the bacteria from chlorine or other chemicals put into the pool to control bacteria. In fact it absorbs chlorine, bromine or ozone so a lot has to be added to the pool to maintain proper levels. As we study biofilm in our laboratory and more fully understand how it affects pools, spas and any other system where water, bacteria and a surface are present, we are convinced that most of the water problems plaguing the recreational water experience are due to biofilm.
The bad news is that bacteria protect themselves with biofilm and that all the chlorine, bromine, ozone, cooper, silver, UV light or other systems that only affect bacteria suspended in water are totally ineffective against bacteria protected with biofilm. The good news is that we are discovering that the sphagnum moss in SpaNaturally and PoolNaturally may be nature’s answer to controlling biofilm.
While this research may not compare with the accomplishment of Apollo 11, in the future we’ll know that cleaner, safer water with fewer chemicals was a dream fulfilled through the scientific effort of hundreds of scientists who transformed our understanding of how bacteria live and protect themselves.
