Magnetic water softners

I bought a house last year and looked into getting a water softening system. The “hard water” problem is that the salts in solution in tap water (particularly calcium, at least in this area) make a hard crust on stuff when the water evaporates, it coats and reduces the efficiency of the heating elements of hot water heaters, and it tends to prevent soaps and detergents from sudsing (is that a word?) A water softener tends to counter the effects of the salts, hence making the water “softer.”

The softening system I looked at had these pellets which were “charged” with a brine solution. The pellets had a slight “permanent” negative charge so the sodium in the brine would tend to cling to it. (You’d have to rinse the pellets with about 10 to 20 gallons of brine about once a week which would then be dumped down the drain and screw up sewage treatment plants which is why I didn’t get one.) When you’d put tap water through the sodium-charged pellets, the calcium in the water would displace the sodium thereby reducing the amount of calcium dissolved in the water. (The other caveat with the system, despite being assured by the salesman that “nothing was added to the water,” was that excessive amounts of sodium were added to the water–enough, in fact, that people with heart conditions are advised to use potassium chloride to charge the pellets instead.)

So anyway, I started looking into alternative systems. Several of them involved magnets (which is actually the point of what I’m asking.) The “basic” models I found were just strong magnets you’d strap around a non-ferrous pipe such as at the street supply. The fancy ones would apply an oscillating magnetic field (some using “low-frequency radio waves”, antennae and all, but I doubted the effectiveness of this) and some would even vary the frequency.

The theory is that the moving charged particles (i.e. the ionic salts moving when you run water) tend to come out of solution when you do this, so you end up with a bit of mineral calcium dust coming out the tap, but otherwise the water is soft. The mineral calcium (I’m intentionally being vague becaus I can’t remember if it’s calcium carbonate, calcium chloride, etc.) takes a long time to go back into solution so as long as you use water say once a day, the system is effective.

There are similar systems which I saw which you’d strap onto fuel lines in cars to keep the various petroleum molecules in gasoline from–this is from the marketers–“clumping together,” which would improve gas mileage, etc.

My question is, to Cecil and all the smart scientists out there, is this stupid?

If a moving, charged particle passes through a magnetic field, it’s direction is changed. This has the effect of disturbing the equilibrium of ions in the water–moreso than vigorously stirring it–so the calcium ions may re-crystalize and come out of solution. However, my guess is that it is stupid because the water is moving too slowly to allow the ions to be “stirred” by a magnet, even a really strong one.

What’s right? I’m planning to do an experiment someday to test this, unless someone else does. Basically allow the same volume of water to flow (at the same rate) through two pipes to two separate containers, one pipe with a magnet, then check the conductivity of the water to see if one has more free ions than the other.

I suppose you could cause the ions to move outward towards the walls of the pipes or, probably better, inwards towards the axis thereby slightly increasing the local concentration. But would it be enough to allow precipitation? I’m doubtful. Wouldn’t the counterion be moved in the opposite direction? It’s extremely difficult to increase the concentration of like charges through magnetic effects; the mutual repulsion is usually so much stronger. A few calculations will show you that ordinary-strength magnets won’t work very well. I guess if the water is really, really saturated it might have some small effect.