So, I have this RainSoft water softener that was in the house when I bought it. Damned if I know how it works. Every couple years I get a call from a RainSoft rep for a servicing, and each time I give them $100 or so- not sure what they do exactly. They haven't been by for a couple years now... maybe 3. Anyway, recently the water pressure in the house has been dropping off at pretty much all the fixtures, the most distant from the tank being the worst. I am guessing that something needs done to replenish/maintain/recharge this unit, but I haven't the vaguest idea what (as you probably figured.) Any suggestions where to begin troubleshooting?