Please help -- culligan water softener problem

[ADRamsey]

We have a culligan mark 89 water conditioner that's about 10 years old and has always worked perfectly, until now. The last time we added salt, things just stopped. The unit seems to cycle (humming noise, water goes out the drain and into the brine tank) but the water is horrible. We have iron and iron bacteria, the taste and odor are awful and it's ruining my bathroom fixtures and we can't wash clothes. We've already taken down and cleaned the brine tank, which seemed to improve things slightly for a day or two, but now it's back to the same old thing; brown, cloudy water with a strong taste and smell. We can't get service in our rural area. Is there something else I should be doing? We've already checked for a salt bridge and we're convinced that's not the problem. Could a clogged line or something else cause this?