Some people consider silver a heavy metal that can accumulate to dangerous levels in the body. I sell a colloidal silver maker but I don't recommend people drink CS on a regular basis, only when they get food poisoning. I mostly use it on the skin to prevent or treat infections. 8 ounces of 5ppm C.S. is 16 times the RDA for silver. Doing this for any more than a week causes a dangerous buildup of this metal in your body to toxic levels. I had a client who got overdosed with silver (40x times normal blood level) from taking 2 tablespoons nightly for 4-5 months which is why I recommend therapeutic dosages only for a few weeks.