What Are the Advantages of Salt-Free Water Softeners?
I actually just replaced my Pelican Natursoft "water softener" with an more-traditional ion exchange model. I used the natursoft for a little over 4 years, and I can say it worked as advertised. When remodeling a while back we decided to get a tankless water heater. All the documentation indicated that hard water with the tankless heater is a no go. We had to do somehting, but since I'm lazy (didn't want to deal with the salt or plumbing in a drain) and my wife didn't like soft water, the salt-free model looked attractive. I too was somewhat skeptical, but the reviews I found looked good, and I know enough about the science of nucleation (I was a material science major in college) to know that what they said made sense, so I bought one.
One thing needs to be made clear - the natursoft system is NOT a water softener! It contains a media which nucleates some disolved metalic salts out of solution. These crystals, once formed, remain in the water, and still react with oils, detergents, etc. in the same manner as the disolved salts. They also continue to form scale wherever water is allowed to evaporate, such as faucet nozels and shower heads. In fact, it's possible that evaporative scaling was even worse than before we installed the system.
Importantly, however, once in crystaline form, these salts do not stick to pipes, or in my case, heat-exchangers. My tankless heater has a sensor to indicate when it needs to be descaled, and the manual indicates that for my water hardness and hot water use I should have had to descale approximately every 6 months. In four years with the natursoft the descaleing indicator has never gone off. For further evidence, when I installed my new softener a few weeks ago, I had to cut sections from the copper pipe on both the inlet and outlet side of the natursoft. Both sections of pipe were installed at the same time as the natursoft, but while the pipe on the inlet side was green and rough on the inside, the outlet pipe looked and felt like new.
As such, if you want or need a salt-free system for some reason (low-sodium diet for blood pressure, don't like the feel of soft water, can't easily plumb a drain into the softener location, or can't carry heavy bags of salt to the softener), then I can unequivocably recommend the natursoft. If, like my wife and I today, you want soft water, that feels soft on your skin, creates less soap scum, rinses cleaner in the dishwasher, etc., then the natursoft probably isn't for you.