converting to salt chlorine still requires the filter and pump. it is an additional part of the equipment. If you are wishing to do this please do a lot of research. there is a lot of misinformation out there about salt chlorine units and pool chemistry.
the way they work is based on your unit manufacturers recommendations you add a certain amount of salt to reach 3000 to 4000 parts per million, again depending on the manufacturers recommendation for their unit. Converting to salt chlorine does not completely negate the possible need to use trichlor and or shock as a boosting effect, especially during the hottest part of the summer. Also contrary to really bad information, one still has to maintain the other chemicals, Total Hardness, PH, Alkalinity, Stabilizer, as well as monitor Phosphate levels. these being correct actually become more necessary in a slat chlorine pool in order to maintain a chlorine residue, and to keep from damaging or destroying the salt cell.
As the salt in the water passes over the energized cell, thru electrolysis it converts that salt to a type of chlorine. most related to liquid shock. this is not a long lasting chlorine, which is why the cell is constantly converting, after a short period of time, dependent on temperature and environment that chlorine turns back to salt, thus repeating the process while the pump is running. the salt is not consumed in this process. Also if one converts to salt chlorine, understand that if one puts salt in the pool and turns the generator on, without an already present chlorine residue, the generator will not be able to produce chlorine. it will try, but it needs to have an already present chlorine level in order to "take over" the chlorine production.
Personally I have used and installed salt generators from Pentair, Jandy, Aquacal and SGS. My least favorite is Aquacal, they are a good generator, but their boards are way to susceptible to shorting out. the pentair system is pretty straight forward, and if there is a problem it usually means the cell needs to be replaced. the Jandy aquapure is good but there have been issues with a bad batch of sensors. My personal favorite from a technician standpoint is the SGS. over 2 years of installing these and I have never had to trouble shoot one installed on a residential system. The only failure I had was on a commercial pool and SGS replaced it pretty quickly. i also like it because you can actually see the cell in its housing and can see when it needs to be cleaned.
just my $.02