Originally Posted by mabrungard
A softener is fine for your non-brewing uses, but don't use softened water for brewing. Many activities in the home can benefit from a softener, but I find that just plumbing a softener to the hot water heater is sufficient to gain most of the benefits with fewer detriments. This way, the dishwasher, clothes washer, and showers are hooked up. The cold water will still be hard, but that is preferred for human consumption.
Those appliances use a mix of hot and cold water. As the cold water is still hard high soap consumption, streaks, stains and crud (the reasons you have a softener in the first place) will still be seen. I don't think this is very sound advice.
Most modern softeners have a bypass valve incorporated so you can draw unsoftened water for brewing when you need it. If for some reason your softener doesn't have the bypass valve then either plumb it in with external bypass valves, install a tee and bib on the feed side or install a saddle valve (commonly used to tap water for refrigerator ice makers) on the feed side of the softener.