It's not all about magnets. Two other nonchemical water treatment systems that have exhibited at Greenbuild for at least the last couple years are worth noting... for one reason or another. During the '06 show in Denver, I spent some time learning about the VRTX—say it "vortex"—sidestream "hydrodynamic cavitation" and filtration system. The company was there again this year. As I understand it (and please do understand that I don't claim to really understand it), it works by blasting two spinning, high-velocity cones of water into each other, which releases high localized heat, creates a strong vacuum, and generally bangs things into each other. A paper assessing an installation at the Ford Motor Company describes it like this:

The VRTX unit consists of a pressure equalizing chamber and a cavitation chamber. Inside the cavitation chamber, nozzles are positioned opposite each other at specific distances, lengths and angles. Water is pumped into the pressure-equalizing chamber at ~94 psig and then channeled into the cavitation chamber. Inside the cavitation chamber, water is forced to rotate at high velocities through the nozzles. The rotation creates a high vacuum (~ -28.5 mm Hg). The high vacuum causes micro-sized bubbles to form and grow in the water streams. The water streams in the nozzles are greatly accelerated and rotate in opposite directions. Upon exiting each nozzle, the opposing streams collide at the mid-point of the cavitation chamber where the pressure increases dramatically causing the spontaneous implosion of the micro-bubbles.

The process is claimed to induce calcium to precipitate; suck dissolved C02 out of the water, which drives up the pH, helping control scale and kill bacteria; and physically rupture the cell walls of microorganisms. Scale and biofouling prevention without chemicals, and potentially saving a lot of water through significant blowdown reduction. It's been on the market for 10, 15 years. The website has the usual compelling case histories—but, like the magnetic systems, statements are made without detailed hooks to hang the science on. (Doesn't necessarily mean it doesn't work.) Could be that it's more info than most people want... but some of us are curious that way. The company may have additional technical literature; I'm planning to ask. One striking thing about VRTX is that they provide a service package and performance contract emulating the ones that the chemical industry offers. For a fixed monthly fee, the company will provide and install their treatment and filtration system, do monthly service and water analysis, monitor bacteria, deploy corrosion coupons, and more.

And then there's—oh boy—Natural Technologies, Inc. If you've been looking for something to flip your wig, dig into this. I'm doing my level best to keep an open mind, but this is a toughie. From the manufacturer's website:

Treatment involves passing the subject water through or around the GRANDER® Technology equipment. The equipment contains sealed chambers of water that has already been placed into a coherent, highly ordered molecular condition at the manufacturing facility in Austria. Acting as a singular system, this water develops a physical field that Johann Grander describes as positive information. When the subject water comes into contact with the information field, the properties of the field are conveyed to the water through molecular resonance. Through interactions within the information field, the degree of correlation, or coherence, within the subject water is increased and the water's molecular structure is improved.

Basically, a sealed vial of magic water (from Austria, not Lourdes) is placed in the flow path. Energy fields emitted by the vial transform the process water into a self-healing state. No electricity, no magnets, no chemicals, lasts forever. (Well, they suggest an expected lifespan of 15 years—but then add, "The life span of a unit will believably continue to lengthen as the GRANDER® Technology continues to grow in the marketplace." Please tell me I'm misinterpreting that.) Yes, they have case studies. Of course they do. I asked them at the show to send me technical literature, but haven't received anything yet. I suspect, if something comes, that it will be this brochure.