Chlorine in the form of tabs, sticks, and granular have been the status quo for pool sanitation in the past.  Although chlorine is an excellent sanitizer, it does have it's drawbacks; the equipment and tools stored along with the chlorine will rust and deteriorate, it has a tendency to fade swim suits, makes the kids eyes burn, and worst of all makes colored hair change color and become straw like.  So looking at the alternatives to straight chlorine there are four segments of devices that can be incorporated into a standard pool system with moderate expense.

• Saline or salt systems - the new breeds of salt chlorinators are reliable and keep the pool sanitized with the production of bleach from the process of ionizing salt between two electrically charged plates.  Ultimately the bleach is converted to chlorine at a fixed interval to sanitize the pool.  The production of sanitizer on hot days and high bather loads requires a normal level of cyanuric acid or stabilizer to be present in the water to hold the chlorine in solution.  Most people find salt pools as they are called easier to maintain and the water feels softer but does not produce the fading of suits or red eye experienced with straight chlorine.  The salt level is noticeable and is generally about 3500 ppm or about the same as human tears. Pentair Water manufactures a very good saline system the IntelliChlor http://www.pentairpool.com/product75/intellichlor-salt-chlorinator.htm
• Ozone generators - these units produce a molecule of O₃ (or ozone) when an electricity is discharged into the air, much like lightning does.  The ozone is quite unstable and breaks down very quickly, but is one of the most aggressive sanitizers known to us.  This ozone is injected into the water stream where it kills all organic matter, including bacteria.  One of the drawbacks to ozone is that once algae has bloomed in the pool, the unit itself will not clear the water.  The advantage is there is absolutely no chlorine and anyone that has an allergy to chlorine can swim in an ozonated pool with out any reaction. Del Ozone manufactures a line of very good corona discharge ozonators and a terrific saline/ozone combination unit http://www.delozone.com/
• Ultraviolet light - it has been know for many years that ultraviolet or UV lighting can sanitize just about anything that is exposed to it.  The power of the light is a direct function of the amount of water that can be sanitized as it passes through the UV chamber of the unit.  This type of sanitation is also chlorine free. Aqua Ultraviolet manufactures a very good pool solution http://www.aquaultraviolet.com/industries/swimmingpools
• Copper Ionizers - when a current is passed between two copper plates, copper ions are released into the water.  The copper ions are an aggressive sanitizer and will effectively attack and kill all organic matter in the water.  A simple addition to the existing system will eliminate the need for chlorine.  These systems require a close eye on the copper level in the water, the PH level, and the calcium hardness to be effective. CL Free manufactures the only microprocessor based solution http://www.clfree.com/index1.htm
• Bromine - While it shares a similar chemistry with that of chlorine, it is a mineral based sanitizer.  There are major differences in how the products are used in a swimming pool.  Bromine is available in solid form and is very slow dissolving.   Typically, it is used in a feeder specifically designed for bromine.  Its main advantage over chlorine is the reduced odor and potential for irritation.  Its disadvantages include:  higher cost, not stabilized for use in outdoor pools, limitations of slow-solubility and requirements for larger-sized, specialized feeders.  King Technologies manufactures the Frog mineral solution for pools & spas  http://www.kingtechnology.com/

• Biguanide (PHMB) - the generic name of one of the more popular non-chlorine, non-bromine chemical sanitizers used in swimming pools.  The main advantage is that no chlorine or bromine is required and there is little chemical odor.  Biguanide is an effective bactericide and can replace chlorine or bromine.  Chlorine or bromine are also oxidizing agents that can destroy organic contamination:  Biguanide cannot destroy organic contamination and, therefore, concentrated hydrogen peroxide must be added to the swimming pool on a regular basis. A disadvantage of Biguanide besides high cost, is the development of Biguanide-resistant micro-organisms, after a few years of product usage.  This usually takes the form of a pink slime or water mold and the only recommended treatment is the application of large amounts of chlorine and/or non-chlorine shock.  Arch Chemicals manufactures the Baqucil line of products http://www.gotopoolstuff.com/baquacil.html

  There are many alternatives to chlorine and our customers do choose them more often now since chlorine has drastically increased in price over the past two years.  Even our commercial new builds are choosing combinations of systems to keep their water clear & clean, the most popular is saline with adjunct chlorine feeder (to meet DHEC requirements).  Another popular combination is ozone and saline.  This method can be obtained in the same unit or two separate systems; either way it is incredible how clean the pool is and what little care it takes to achieve those desired results a pool owner wants.