Saltless softners are a joke, IMO, and don't actually do anything. Sure the companies tell you that they do, but all scientific tests that I have ever seen refute their claims. Things like magnets or aligning the ions with an electrical coil, etc, are so much hog wash, kind of like the magnets you can supposedly put on the gas line in a car to increase mileage. They don't do squat!.
Softners work via the ion exchange method, where the hardness, (calcium and magnesium ions) in the water are readily exchanged with sodium ions from the mineral bed in the softner. So the water isn't really "salty", it just has a higher sodium level than it normally would. The chloride portion of sodium chloride goes down the drain during the brining and rinsing cycle, while the sodium stays behind to be exchanged with the hardness ions in the water.
The mineral bed has a stronger affinity for the hardness ions in the water than the sodium ions, so one is easily exchanged for the other during normal operation. Each bead of mineral in the softner can only hold so many hardness ions, which is why the softner must be regenerated periodically. A strong sodium solution is required to make the mineral beads exchange their hardness ions for the sodium ions again, hence the brine solution required to recharge the softner.
Softners aren't really designed for iron removal, and don't work that well if the iron level is over say 2.5 ppm. But they will remove iron, strictly as as a filter, not by the ion exchange method, if the iron level isn't too high. If you have iron in your water, it is better to regenerate oftener and lower the amount of salt per regeneration. THis is because iron needs to be flushed out frequently by regenerating the softner, otherwise it can clog the softner by binding the individual mineral beads together in ever growing clumps until the softner doesn't remove either hardness or iron well anymore.
Don't use the green bag salt with iron remover in it. You are much better off getting the standard salt, and adding your own Iron Out to the salt. You get a lot more oxidizer than is in the salt. Even better, is to take a pound or so of Iron Out, mix it in a few gallons of warm water to desolve it, and then dumping it in the brine tank. THis will shock the softner and do a much better job of removing iron build up in the softner than constantly feeding it a very minimal amount of Iron Out constantly. Depending on your iron levels, you can do this say monthly or so, and keep your softner in great shape.
As for softners, no matter what anyone says, they all are about the same, and work about the same way. Kinetico uses a slightly different mineral, that costs more and is supposedly more efficient, but definitely not worth the HUGE premium that they charge for it, IMO. Sears is a good softner, and they sell more than everyone else put together, but it is a throw away unit, and generally not worth repairing. Parts change rapidly, and can be hard to get, but for something that only costs $400 or so, throw it away and replace it. Most private labeled units are no different than many other softners, but are sold via salesmen that get 50% +- of the sale price as commission, so they are way over rated, and over hyped. Definitely not worth the high price you pay versus other similar brands.
Most softners have the same controls. Made either by Fleckinstein or Autotrol, and then private labeled. Kinetico, Sears and Culligan (sometimes) have their own controls, but most others use one of the big two, and then try to claim that theirs is so much better than the others! Nothing but marketing hype.
