I have one of these same units and am having the same problem. The thing has never correctly identified the water salinity. (Either this year or last.)

The pool didn't get completed until Augsust, and as it is a gunnite/plaster pool I waited a month to hook up the unit. Added salt to 3250 but the IC never came off of red. Can't rememger where the add started but I was into the 4000's (think around 4200) before the IC finally said I was at the minimum good reading. [And this was adding one back of salt, and then later a half bag, at a time and waiting to see if the unit would turn to green.] At that level you could taste the salt in the water, not as bad as the ocean but definitely reminiscent. Called Pentair and they recommended the PB calibrate the system, since under warranty they would send someone out if needed.

Somewhere last year someone got the directions from Pentair on how to set these units but he didn't post it. If anyone finds this info please pass it on as obviously it is needed. (Note: my PB at the end of last year said he'd just found out how to do it and said it had something to do with holding down both the more and less buttons for a period of time, or something like that.)