I would go on the Ask Trapper forum and scroll down the last week or two's posts. There is a ton of information there. Through him I just bought a Dyna Chi Ionic Body Balancer....it is what they call a BEFE model.
Good luck...I know it's confusing.
PS: There is a great deal of talk about the color of the water. My understanding that that the water color doesn't mean much. It will change color even if you don't put your feet in it. that said, I will die if I see any worms.