A few years back this forum was great help in helping me replace a stuck piston on this softener head. I was away for several years (child living in house) and when I recently returned I found what looks like sand/grit in my salt tank. The hot tub would also show sentiment after filled/drained. I flushed my water heater and put a new anode rod in... water in tubs now clean. But the grit is still in my salt tank. I let the salt run really low with the idea of dumping it and then cleaning the brine tank out before refiling with salt. However, last recycle I ended up with a Err! message on the console. I don't see it in the user manual. Could this be caused by the brine and water being so low in the salt tank? Second, any idea what could cause that grit in my salt tank that happened over a period of years? Thank you this forum has been really helpful over the past +10 years.