The Salt Water Chlorinator unit is located in the pool plant room, when the pool filtration is on the mildly salt water passes over the Salt Water Chlorinator Cell. Electrolysis breaks the salt in the pool water down and produces a Chlorine gas which is used to sanitise the pool water. A salt water chlorinator will constantly produce a very low level of chlorine in the pool that is used to sanitise the pool water. You can simply adjust the output of the machine depending on your use. If you are going away for a week or month you can simply decrease the sanitation output or if you are expecting lots of pool use, you can simply increase the output.