Was at my lfs and was trying to find a way to keep my ph up in the ray tank. They said to use these. The're for saltwater but i read the minerals it releases and one of them are copper. Now i heard that copper is REALLY bad for rays. Is this a known fact, should i stay away from this stuff. I called the manufacture and of course no one called me back. Any help would be great. I know you all will reccomend the drip but our water around here is like GOLD. Thanks