Chlorine Products Used Today
Most of you are already familiar with the types of chlorine used in swimming pools (calcium hypochlorite, sodium hypochlorite (bleach), lithium hypochlorite, dichlor, and trichlor). The first three are not stabilized. Meaning once exposed to the sunlight, it will quickly precipitate out of the pool and/or be converted to chlorides. This is why dichlor and trichlor have become so popular since the stabilizer is added into the dry chlorine.
You are also probably familiar with a “salt pool,” or a salt water generator (SWG) which converts sodium chloride salt into chlorine. I am still amazed of many people still do not understand that salt water pools are chlorinated pools. It simply converts chlorides into chlorine (hypochlorous acid and hypochlorite ions when in water). When the water chemistry is properly maintained, SWGs can drastically reduce the need to shock your swimming pool. The downside is that overtime, SWG pools can be corrosive to the coping and decking. If you have a vinyl liner pool, there is a chance that the frames behind the liner will corrode which is a very expensive fix. Do not be fooled, since it is a chlorinated pool, you will still have the same disinfection byproducts as a traditionally chlorinated pool.
There is a growing segment of the population that is concerned with the toxins in our environment and are living healthier lifestyles. There is a debate going on now if there is such a thing as chlorine allergies (I will leave that up to the medical doctors). However, there is a general consensus that a small percentage of people are actually hypertensive to chlorine. There is also a decent amount of evidence on increased asthma in young athletes which are involved with competitive swimming in indoor chlorinated pool. Only time will tell, but consumers are not wanting to wait. This is why more consumers are seeking a chlorine alternative.
Bromine is in the same halogen family as chlorine. It does have its advantages and disadvantages. Unlike chlorine, it cannot be stabilized with a product such as cyanuric acid. This is a problem with outdoor pools since the sun will quickly burn off the bromine. Bromine would need to be constantly added which would become costly. Now is does have advantages over chlorine for indoor pools. Bromine with not produce a gaseous byproduct like chloramines which are very irritating to the eyes and can cause a strong odor. Chloramines has also been linked to an increase in asthma for swimming athletes. The byproducts of bromine and its effects are not fully known at this time.
Baquacil, Aqua Silk, and Softswim use polyhexamethylene biguanide (PHMB) as the active ingredient. The main advantage PHMB has over chlorine is it is not an oxidizer and it is not significantly affected by sunlight. Therefore, PHMB residuals are much more stable in both pools and spas than chlorine. The disadvantage is that it is not an oxidizer and a 27% hydrogen peroxide shock treatment is necessary for clarity. These products do not irritate the eyes or skin. These products are by far the most expensive choice in maintaining your swimming pool. Expect to pay more than double to maintain biguanide pools.
PristineBlue has an active ingredient of copper sulfate pentahydrate. Copper is a very effective algaecide. Like the aforementioned products, it is not an oxidizer so you will need periodic shock. The problem is that anything that you need to maintain the pool, you should stick with its complementary and proprietary products. This can get expensive but perhaps not quite as expensive as biguanide based products. Not all stores carry this product so one may spend a lot on gas trying to locate it.
Non-chemical pool treatments would include pool ionizers (copper, copper/silver, copper/zinc), mineralizers (Pool Frog, Nature 2), ozonation, and U/V Light. Mineralizers, ozone, and UV lights do not provide a “residual” for sanitation and the biocide component is short lived making it a poor choice as a primary sanitizer. Do not get me wrong, they do offer wonderful benefits. They all reduce the amount of chlorine that is necessary to maintain a pool. Ozone and U/V are becoming more popular with the combined use of chlorine to reduce the disinfection byproducts (DBP such as chloramines) and can reduce the frequency of using shock treatments. Of these non-chemical alternatives, only ionization has a long lasting disinfection which makes it the most attractive option. Ionization can be used with anything listed above including chlorine. If pool ionizers are size and the water chemistry is maintained properly, then you can have a “chlorine free” pool.
Ozone is a very strong oxidizer and is used for many applications. Intec has used ozone quite a bit for treating high levels of iron, iron bacteria, as well as hydrogen sulfide. I traditionally have not been a huge fan of ozone for swimming pools. It is quite expensive and does not offer all the benefits I am seeking. It can reduce chlorine levels required for swimming pools and is effective a reducing chloramines which also reduces how often pone might need to shock a pool. Ozone still cannot sanitize a pool on its own, but when combined with copper ionization it can be a great clarifier and offer a multi-barrier sanitation approach. The best technology available for the copper ionization and ozonation approach is the Solar Eclipse from EL Ozone which offers a mixed oxidant though is AOP technology. The MSRP on these units is $2,300.
UV or ultraviolet light is a concept I still do not see how it made it into the swimming pool market. I do like UV light being used in a closed loop system such as point-of-entry for a home. I have sold quite a few of them. The sanitation takes place inside the quartz sleeve (a clear tube water flows through running parallel with the UV bulb). So if a pool recirculates every eight hours, you have once chance to get the bacteria, virus, or algae spore. Bacteria and algae do replicate a lot faster than this (algae can double itself every 15 minutes). UV light can convert chloramines to chlorides and I can understand this advantage to a point. However, calcium will scale over the quartz sleeve making it not as effective after a few weeks. It is just another widget being sold so more money can be made.
Copper ionizers is the best chlorine alternative on the market today. Ionization has been around for a couple of decades and there has been quite a bit of advancement. Ionization is the process in which a current is supplied to a sacrificial electrode made of various metals and subatomic particles (ions) are pulled off as water passes though the electrolytic cell. The composition of metals/alloys include copper, copper/silver, or copper/zinc. These metals are toxic to many forms of bacteria and algae. At recommended levels, it is totally safe for humans and animals. It is important that only high purity metals are being utilized in the electrode. Otherwise, impurities such as carbon can stain a pool black. It is also important to go with a company that has been around a while. Many manufacturers have entered the market place and left in just a couple of years. This is a nightmare for warranty or replacement parts such as electrodes. If manufacturers have not been in business for at least 10 years, do not even consider them regardless of their technology or sales pitch. Also make sure you evaluate the replacement costs of the electrode. There are a few companies that offer $300 ionizers that have a replace electrodes for $170. Most are very small and the life is only 3 months. If you have to replace these several times a year, it becomes very expensive. More advanced systems may be more expensive upfront cost but have electrodes that lasts 2 or more years. These units are also more powerful and can replace chlorine altogether. Smaller systems and solar units to not have enough power to treat a 15,000 gallon pool for example despite their claims. What good it is it you have to run it an ionizer 8 hours a day every day to maintain copper levels. If you have algae present, it will never keep up. These cheap systems have given the ionization a back eyes on its reputation.