I ran into this product elsewhere and also had some contact with the company, read the patent, etc. The results so far have been mixed from the few people who have tried it. Unfortunately, for many they didn't have measurable metal ion levels to start with so it is hard to know if it works in such cases. There was a case that seemed to work, but we just don't have enough to be conclusive. So the jury is still out on this one. I had high hopes initially since there isn't much that actually removes metals from the water as opposed to sequestring them (except for Ben's "precipitate it into the filter at high pH" method). I have a bag still in my skimmer, but I've never measured metals though have a yellowing light stain that seems to only appear at higher pH so I figured it might be iron (I have rusting stainless steel mounts where my Trichlor floating feeder caused corrosion 7-8 years ago).