Alternative sanitizers have had their ups and downs over the years but chlorine has always been king when it comes to popularity. Here are some of the alternatives when it comes to sanitizers and the positives and negatives.
Bromine is a sister chemical to chlorine and is more stable in higher temperatures so it makes a great option for spas. Bromines big advantage comes in its ability to sanitize in spite of chloramines. Chloramines are a combination of swimmers waste that forms with chlorine or bromine in the pool water and will lock up chlorine making it inefficient in its attempts to sanitize the water. To eliminate this problem when you are using chlorine you have to shock treat the pool to “burn off” the chloramines. The advantage bromine holds over chlorine is that the chloramines do not interfere with bromines ability to sanitize, they continue to kill bacteria and algae in spite if chloramines. Bromine is also more efficient at killing algae than chlorine is, however there is a down side to bromine it cannot be protected from evaporation by UV light. So when the sun hits the pool it will take the bromine out of the water rapidly leaving your pool water defenseless. This is why bromine is better in spas or indoor pools (which don’t have the UV light issue).
Biguanides are a non-chlorine alternative to the traditional sanitizers like bromine or chlorine. Biquanides are sold under many different names but the two most common are Baquacil and Soft Swim. We primarily sell the Soft Swim products. This product was very popular in the late 80’s and the 90’s but has lost market share over the last 10 years with the increase in popularity of salt generators. The Biguanides are not nearly as efficient as chlorine when it comes to sanitizing. It takes a Biguanide substantially longer to kill bacteria than chlorine does. The systems work well but there are some things you need to understand about how the product works and how to apply the product before you make the commitment to a Biguanide. The first thing to keep in mind is that you have to follow the manufactures recommendation perfectly and if the water gets over 80° you will have to go beyond the normal recommendations.
The normal regiment for a Biguanide is first shock the pool monthly with a 27% hydrogen peroxide at the rate of 1 gallon per 10,000 gallons of pool water. If the water temperature is over 80° you will need to shock it every 2 weeks and if the water temperature goes over 90° you will need to shock it every week. The bactericide should be maintained at a minimum of 30 ppm and you need to add the algaecide every 2 weeks. If you follow these minimum directions you should have few problems.
If you do have problems this system is less forgiving than chlorine or bromine and can take a long time to correct problems. One other product you can use with this system that will make using it easier is BorX an algae inhibitor. This product usually reduced the bactericide usage by about 25%.
One of the down sides to this system is cost, a typical 30,000 gallon pool will cost $800 plus for a season of chemicals and the cost can go up if you have a problem. The other thing is that this product is not compatible with most other sanitizers on the market so getting off a Biguanide can be a several week process. One of the great things about the Biguanide is that it lasts a long time in the pool and one of the bad things about a Biguanide is that, when you are converting the pool back to chlorine, it lasts a long time in the pool. If you are on this product and want to convert we can help you do that, if you want to go to this product we can help you with that as well.
Two other popular alterative sanitizers are ionization and ozone. Both of these systems are not stand alone systems but are supplements to some other form of sanitizing that allows you to lower your sanitizer levels.
Ionization comes in two different forms passive and active. The active form has a probe that has either silver and copper or silver and zinc, attached to the probe is a wire that would apply a small electrical charge that will cause the minerals to be released into the water. The reason you should not use this system as a stand alone sanitizer is because the kill rate is substantially slower than that of any other sanitizer and you need to have something that will be more active, like chlorine, to have a fast kill rate. Probes will usually last 3 to 5 years before they need to be replaced. The down side to this type of system is that if you are using copper as one of the elements there is potential to stain the surface of the pool and perfect water balance needs to maintained in order to avoid this problem. The other problem is you are restricted as to the type of chemicals you can use to solve problems you may encounter with your pool making problem solving more difficult.
The other ionization system is a cartridge system that has all the water pass through the cartridge and this is where the bacteria and algae come into contact with the minerals. These cartridge are designed to last about 6 months, typically a pool season in this market, then they have to be replaced to be effective. This type system will give you similar benefits of the release type of ionization but offers more options when it comes to problem solving should you encounter problems with your pool water.
With both types of ionization systems you would maintain a chlorine level of .5 ppm in order to kill bacteria and algae quickly. Normally you would maintain a 1 to 5 ppm with a chlorine system. Both systems can be combined with salt generators if you desire.
The other type of alternative sanitizer I mentioned is ozone. Ozone is a gas the is composed of 3 molecules of oxygen, instead of the usual 2 molecules we breath in the air. Ozone is a very effective bacteria killer. It actually kills on contact which is faster than chlorine kills. The problems with ozone are first and foremost you cannot maintain a residual of ozone in the water, as within seconds of being created the ozone dissipates from the water and is gone. So you still have to maintain a chlorine residual to keep the water sanitary. The other thing is ozanators for pools are expensive. Ozone is ideally used in spa applications and indoor pools. There are two methods of producing ozone; UV light and Corona Discharge. The UV light is not as reliable as the Corona Discharge, but UV light is more cost effective.
So there you have it for sanitizers. If you have more questions about this article or any other articles in our Pool School series please feel free to contact us. In Pool School 103 we are going to be talking about pH and why it is important in your pool. Make sure you are on time for class!