Continuum Aquatics Power Cleanse HM Heavy Metal Remover - Regenerable Filter Resin for Copper & Metal Removal in Saltwater & Freshwater Aquariums | Ideal for Reef Tanks, Fish Tanks & Aquatic Ecosystems

I bought this after my reef tank start doing poorly and several corals were dying or closing for a long time. I thought that maybe some chemicals released by the corals or metabolite from leftover food 30th my tank, and therefore I started using activated carbon to get rid of that, together with regular water changes. That didn't do anything. Then I bought this product and very quickly my tank start getting noticeably better. So yes it is expensive but it seems It's still worth it. My water quality must have improved considerably. It lasted for several months but now it's again bad. I used maybe 1/4 of the jar for the first treatment and I left it in my filter for about 3 weeks. I think I will have to use the same dose again, now the one year later. I will edit this post with the results of the second treatment.