Creative Water Solutions

Natural Water Treatment for Pools, Spas, and more

In my continuing travels to dealers, shows and meetings I am frequently asked, “Does the moss work in a salt water pool? “ Or “why do I need moss since my pool doesn’t need chlorine since it is a salt pool?” So this blog is about the science and chemistry of salt-water pools.
First, definitions: I’m going to talk about pools where the sanitizer is made from salt by a generator – not about the very few pools that actually have salt water similar to that in the ocean. Second, when I talk about green pool products I’m using the word to describe a product that is sustainable, with no artificially made chemicals, that doesn’t introduce toxic chemicals to the air, water or ground.

How does a salt water pool work?

Salt is usually sodium chloride or potassium chloride. When these chemicals are in water they become positively charged sodium or potassium and negatively charged chloride ions. In a salt pool, solid or crystalline salt (like table salt) is passed through a generator that produces hypochlorous acid and delivers it to your pool.
This is the exact same chemical that results when you place chlorine in your pool. Salt generated chlorine doesn’t add cyanuric acid in addition to the chlorine, which is added when “stabilized chlorine” such as dichlor or trichlor are used.
So a salt pool is simply a different way of delivering chlorine to your pool to make hypochlorous acid. It is no greener or different than using liquid or solid chlorine. Again, the end product that works to kill bacteria in water is hypochlorous acid and whether you produce this from salt, or deliver it to the water as chlorine, it is all the same thing.

Is a salt pool greener?

The short answer is no. People who sell salt generators want customers to think it is green since it uses salt that doesn’t have a bad name vs. chlorine that had a bad reputation. The end result of each method is the same production of hypochlorous acid that causes the exact same problems with pool water regardless of how the chlorine is delivered to the water. Salt-water generation of chlorine is no greener than adding bleach or granular chlorine to the water.

Does moss work in a salt-water pool?

The short answer is yes. It works the same way whether the sanitizer is added chlorine, bromine, cooper or silver salts, or ozone. It has the same positive effects with all types of sanitizers (except biguanides).
In our customer’s experience using moss with a salt generator, the amount of salt consumed by the generator decreases by 80-90% to keep the free chlorine in the pool between 1-2 ppm. This puts much less strain on the salt generator and results in less chlorine being added to the environment. The other effects of moss, such as pH stabilization and organic contamination effects are the same.

Organic Contamination

A couple of weeks ago I attended the World Aquatic Conference in Atlanta that focused on health and safety issues in aquatic recreation. There were a few sessions on Cryptosporidium and pool contamination.
A long time ago I spend three months in rural Ivory Coast in Africa and saw the effects of parasites on health. There it is a daily, widespread and often fatal problem. Trying to eradicate the parasites is impossible, so most of the medical effort centered on treatment. Luckily, we have very few parasitic diseases so general knowledge about parasite patterns of transmission and growth are widely known.

Parasites in Pools and Lakes

Cryptosporidium, or Crypto for short, can be a serious health problem from pools and lakes. Giardia in lakes is a type of Crypto. Both parasites set up home in the intestines of mammals and cause diarrhea with the accompanying dehydration.
Contrary to most people’s belief, these parasites do not proliferate or “grow” in the water – only inside mammal’s intestines. They can live in the water for long periods of time waiting for an unsuspecting mammal, maybe you, to swallow the water. Then they set up shop and start to divide causing intestinal disease. Huge numbers of Cryptosporidium parasites can reside in every stool from an infected animal or human. As few a 10 ingested organisms can cause serious disease.

Read the rest of this entry link

 

Now that you’ve flushed your spa once, twice or as many times as it takes to get it all out, how can you prevent organic contamination from forming again?
Remember – organic contamination forms when bacteria in solution adhere to a surface, divide and cover themselves with a protective layer of slime (mucopolysaccaride). Learn more at Montana State University’s CBE site.
You could try to completely sterilize your spa and the spa water and keep it sterile; drain the spa and use fresh water every week; use a flush to remove all organic contamination once or twice a month and replace the water; OR you can prevent formation of organic contamination while killing all swimming bacteria. Let’s look at each one.

The Hard Way:
Sterilize your spa and water

There is no easy way to sterilize every surface in your spa short of sending it to an industrial sterilization facility that uses high power x- rays. Even if that was done, the water placed into the spa would have to be sterilized, and you couldn’t use the spa because the second you stepped into the spa the bacteria on your skin would quickly repopulate the spa water and the spa surface. In my research laboratory, we conduct many experiments under sterile conditions and keep the systems sterile. The amount of work and equipment in addition to training required to accomplish that is enormous.

Drain the spa and use fresh water every week

This is essentially how commercial spa operators try to keep their spas within health department guidelines. They often use a measurement called “total dissolved solids” to determine when to dump the water and start fresh. Depending on the bather load, this could be done twice a week or weekly. The water is then treated with a sanitizer like chlorine to keep the bacteria count in the water within safe limits. This approach uses a lot of water, takes a lot of time, and does nothing to address the formation of organic contamination in the spa. With the organic contamination present in the spa, any excess bacterial challenge or change in bather load will “tip the balance” of the water and require more frequent water changes.

Use a flush to remove all organic contamination once or twice a month and replace the water

As we discussed in my last blog (September 23, 2009), we now have an effective flush system that efficiently remove organic contamination from surfaces and keeps it in solution. When the spa is drained, the organic contamination goes out with the water. With fresh water and sanitizer in the spa, new organic contamination will form over time requiring reflushing and fresh water. Theoretically, the water should last longer between changes than the previous scenario, but with frequent spa use, flushing would have to be done once or twice a month. The same problems as above make this treatment plan a real problem.

The Easy Way:
Prevent the formation of biofilm and control the number of swimming bacteria

This solution is ideal. Up until the discovery that certain species of moss prevent the formation of organic contamination, this was a just a theoretical possibility. We know that sanitizers like chlorine and bromine are very effective killers of bacteria that swim. We now know that these same sanitizers are absorbed by organic contamination and fail to kill all the bacteria within the organic contamination.
Here’s how we now think this works: Combining the moss with sanitizer solves the problem. The moss prevents organic contamination from forming, allowing the sanitizers to efficiently do their work on planktonic (swimming) bacteria. The moss also inhibits bacteria from dividing, so there are fewer swimming bacteria to kill. Combined with the moss’s ability to remove heavy metals from water and stabilize pH, the spa water becomes stable, clean, clear and safe. See the video on our website for more information

In my last blog we discussed organic contamination and how it affects your pool, spa, home, really anywhere water, bacteria and a surface come in contact. It is an important new discovery that is helping us understand how to keep water clean, safe, crisp, clear and provide a pleasant experience. You can see a newly posted, short video about organic contamination and Sphagnum moss on our website.

How do I get my spa, or pool to be organic contamination free and keep it that way?

So the question remains, how do I get my spa, or pool to be organic contamination free and keep it that way? First, if you haven’t done anything to remove the organic contamination or keep it from forming, then be assured you have organic contamination on every surface. It is very difficult to remove organic contamination once it has formed.
The best example of how difficult it is to remove organic contamination is the tartar on you teeth. That is organic contamination and all the brushing, flossing, and mouthwash use will not remove the tartar. Your dental hygenist has to scrape it off with sharp (an often painful) tools. It would take toxic acid to remove the organic contamination. That would destroy your teeth and gums along with the organic contamination. Scrubbing the surface of your pool or spa might remove some of the organic contamination, but not all of it. If it isn’t totally removed, any remaining will re-infect all the surfaces and restore the organic contamination in hours. All the interior surfaces of your spa or pool are impossible to clean.

Spa System Flush
I know of one chemical that is EPA certified to remove organic contamination. We tested it. It did remove some of the organic contamination, but it off gassed a chemical or chemicals that were very toxic to my lungs and all those in the same room. We found a spa flush that claims to have an effect on organic contamination and it does break organic contamination free from the spa and doesn’t cause any severe side effects. This is supplied in our SpaNaturally® kit (Spa System Flush).
Soon we will be releasing a new solution that is even better at removing organic contamination with no side effects. We test these products in our laboratory on organic contamination grown in cultures and then also test them in the field.

The bad news for spa owners is that they need to flush the spa to remove organic contamination whether it is new or old.

Here’s the problem: When spas are made at the factory they are tested for leaks by filling them with water from tanks in the factory. organic contamination grows in these tanks so the water transfers bacteria and organic contamination to the new spa. It is impossible to remove all the water from the spa. It is then shrink wrapped and stored. Everywhere there is water there is organic contamination that dries and hardens as the spa is stored.

brand new spa being flushed!
When you refill your new spa the dried organic contamination comes back to life and spreads throughout your spa water. Another fact is that the more jets in your spa, the more organic contamination there is also. Each jet is fed by a tube made of plastic that comes from a manifold. The more jets, the more pipe, the more places where water collects and forms organic contamination.
I proved this by using a long scope like those I used to use for colonoscopy. In a new spa, the tubes leading to the jets were clean until they curved. Along the bottom arc of the curve the organic contamination started and continued until the tube curved back either up or down.
Another place where organic contamination forms is in the housing of pumps. These are wet tested in the factory and have the same problem as the spa jets. In fact, I recently had to replace my circulation pump in my own spa that is organic contamination free. Three days later the water became cloudy and started to foam. I flushed the spa and black organic contamination came out with the flush. After flushing the spa returned to crystal clear water, with no foaming. I then checked other pumps and found black organic contamination in the pump housings.
Heat also affects organic contamination formation. Bacteria and organic contamination are very temperature sensitive. The closer the temperature of the water gets to 100°F the higher the bacteria growth rate and therefore the more organic contamination forms. Lower temperatures inhibit (but don’t stop) bacterial growth.

How much flushing is needed?

Depending on the amount of organic contamination in the spa, more than one flush may be needed to completely remove all the dried biofilm. I needed to flush my new spa seven times (using our current flush) before it stayed clean and clear.
You are probably asking the same question I did while this problem was being understood and researched. Could the spa manufacturers make a organic contamination free spa? I know they can. We have been working with spa manufacturers to flush their water tanks and treat the water with moss so they don’t transfer organic contamination to the spa when it is wet tested. So far, the results are very encouraging. When we flush the new spas, very little organic contamination is removed even after months of storage.
In review. organic contamination coats all spa and pool surfaces in contact with water. It is very difficult to remove. Using the right chemicals and system can remove organic contamination. All spas, new and old must be flushed. On the horizon, biofilm free new spas are possible.
Next, I’ll talk about pools and preventing organic contamination from forming.
David Knighton, MD