I have a Hayward Swimpure system, SWG is 3 years old and kept spot less. The salt level in the pool was tested professionally at 3200. The issue; I purge the system per one of the posts on this site to clear the memory then re set the salt level to match the tested level. All is ok. I then check the salt level then next day and it is at 2500 or less which does effect the generation of chlorine, not very efficient. What is causing this? Is this an early signal that the SWG is on it's last leg or the board? Like I said "Uncle"!