Typically in standard chlorine systems, the chlorinator is connected to the filtration system. Chlorine is added to this system either weekly or biweekly basis to maintain proper sanitizing levels. The chlorine added to these systems is a stabilized type of chlorine and often have PH balancers, clarifiers and algaecides built in to them.
A salt generator (also known as a salt system or a salt chlorinator) consists for a control box and a salt cell and is installed on the pressure side back by the filtration system. Using metal plates and an electric charge the salt cell, through electrolysis, produces Hypochlours acid, a non-stabilized form of chlorine which has a very high PH. A salt water pool is technically sanitized by chlorine even though you don’t add it to the pool instead it is produced by the salt generator. Because the salt system produces the chlorine there is no need to purchase, store or handle the chlorine. It is also generally less harsh to swim in and the water feels “Softer”.
Things to consider when changing to a salt water system:
Salt systems are not maintenance free. Because of the high PH associated with non-stabilized chlorine, regular testing to keep PH and total alkalinity in proper balance is necessary. High PH associated with salt systems can produce heavy scaling on pool surfaces.
Along with a salt system you should also install an inline sacrificial anode to minimize corrosion on pool equipment. Any qualified pool professional will suggest this at installation of the salt system, because without one, the reaction of metals in your pool along with the salt solution will damage everything in your pool from vinyl walls, stainless steel screws in the face plates, light rings, step trims as well as the anchor sockets which hold the rails and ladders even causing premature failure of heater components.
Items such as handrails and ladders which are normally made of steel should be converted into some sort of composite, sealed steel, or plastic which prevents corrosion.
Consider your coping and decking many decks are not salt friendly like travertine, flagstone, cultured stones, types of blue stone, limestone, clay tile grout, etc. These surfaces can be resealed more often to help prevent damage.
City or town ordinances regulating the draining of salt water pools. In some cases salt systems are prohibited if the pools are connected to the sewer systems.
In general salt water systems are about the same as far as long term costs. Initial set up is generally more money for a salt system. Costs on chemicals to maintain it may be less however salt cells are upward of $1000 to change out so costs generally equal out over time versus standard chlorination. Salt is however preferable to many due to the less harsh odor and improved feel of the water. If all precautions are taken as far as installing the right equipment and making sure your decking and surfaces are suited well to withstand the salt it might be a preferable option for you.