I read all the posts above. One mentioned if the CS that was used caused a herx then it was effective. That cs was made by my Silvergen SG6. The most effective ppm is about 10-20ppm with a portion that is about 95% ionic. By the way none of the batches I have made have ever turned yellow or darker indicating larger particle size. The constant current keeps the particle size very small and will stay small because the range is preset from 3-20ppm with the variable ppm dial. There aren't any better home units than the silverpuppy and the silvergen, either will make an excellent quality cs and both have very similar internal settings and components.