We used Collidial Silver in the cat shelter for some time. We added it to the water as a preventative. It apparently has antibiotic as well as antifungal properties. Not sure if it helped or not at any rate it did not do miraculas healing or anything (we still had ringworm and URI) and it was cut from the budget due to enormous expense of it, but occassional I will use in tap water in the attempt to kill unwanted organisims; doesn't do anything for the chemicals though. The literature claims it was used before antibiotics were discovered for infection etc. Sorry not much help, but you should be able to find info on it.