Thanx Watermom for the welcome. Yes, we're aware of copper turning things green. The pool isn't an issue - no staining after 4 years. Fingernails not a problem either. Hair is another story. Of the 4 people who use the pool almost daily, two are dark blondes, one dark brunette with some grey and one white (me). I'm the only one with green hair which I use a clarifying shampoo to take care of. Our water condition has been excellent using the Water Doctor (not something we have to use all the time). Thanks for the caution tho. Mrs. DanMan