Salt or Brine Chlorine Generators
Salt generators basically produce chlorine from salt. While salt generators require that you purchase salt instead of chlorine, you are still swimming in chlorine and you will experience all of the problems you will experience swimming in a chlorine pool.  Salt generators are expensive devices and consume a lot of electrical current.  Salt generators are also very corrosive and the generator chamber has a limited life, and is expensive to replace.

Biaguanide Chemical Products
Water purification additives containing biaguanide chemicals are sold under the trademarked names of Baquacil and Soft Swim.  The active ingredient in these products is known as biaguanide.  Unlike chlorine, biaguanide is not an oxidizer, so it does not irritate your body by “burning up” organic contaminants like chlorine.  Biaguanide does provide a higher quality of water than chlorine treatment but it is very, very expensive.  Sometimes costing several times more than chlorine.  Biaguanide needs to be purchased in bulky containers, and needs to be manually added to the pool water regularly.  After prolonged use of biaguanide, some pool owners complain that it takes more and more of the product to achieve the desired water quality.  Pool owners also mention that the product causes a unique odor in the water after extended use.

Ozone Generators
Ozone generators use a special ultra-violet light to kill bacteria. Like the cartridge systems mentioned above, ozone generators only kill contaminants in the ozone chamber and provide no residual protection to the water in the pool. To be effective, the pool pump must run almost all of the time. Ozone units designed for swimming pools are very expensive and draw a lot of electric current. These units are better suited for spas but are not practical for the volume of water in most swimming pools.  Even the best ozone units will not totally eliminate the need for chlorine or other chemical oxidizing agents in the pool water.

Ionizers, electric or solar
There are numerous ionizers on the market today.  Some are solar floating ionizers, some are electric copper and silver ionizers and others are electric copper ionizers. In general terms, ionizers do a good job of killing organic substances in the water but ionization alone is not sufficient to sanitize your swimming pool water.  Ionizers still require chlorine or other toxic chemical oxidation to be added to the water to provide adequate sanitation of the water.

Chlorine or Bromine Chemicals
Chlorine is still the most popular means of sanitizing swimming pool water. It does an excellent job sanitizing water, but it does so at a huge price. Chlorine is a very caustic, corrosive chemical. It is effective because it attacks anything organic. Unfortunately, it also attacks the skin, hair, and eyes of the humans swimming in it. Chlorine is toxic and hazardous to handle, ingest or breathe. It is also dangerous to store. Chlorine can be extremely flammable. Chloramines, a by-product of chlorine and organic waste, are known carcinogens. Unfortunately there is no practical way of preventing chloramines from forming in chlorinated swimming pools. Maintaining chlorine levels at minimal acceptable levels can be very difficult to do at times. Residual chlorine is highly affected by the water temperature, rain, pH, and number of swimmers.  Chlorine is absorbed in the skin of swimmers, therefore the more people that swim in the pool, the more chlorine is absorbed by their skin and the more chlorine that needs to be added to the pool to properly sanitize the water.