Cuprex is "free ionic" and chelated??

[piercho]

Can a copper sulfide medication be described as BOTH "free ionic" and "chelated"? I just want to have a bottle of copper sulfide on standby while I bring some new fish through a q-tank. I got Aquatronics Cuprex (http://www.aquatronicsonline.com/product/product5.htm) at the LFS because the box said it was free ionic copper. I got it home and the bottle inside the box says it is chelated. The web site says it is "Chelated to ensure active shelf life". What the heck - chelated with what? I guess the real question is if I need to use this stuff and keep it bumped to the lethal-to-protozoan zone as monitored with a FastTest copper test kit, am I dosing at an effective level? Sorry but I searched this forum and the fish disease forum for Aquatronics Cuprex over the last year and got no hits.

[Randy Holmes-Farley]

I presume that you mean copper sulfate. Copper sulfide is something totally different, and it shouldn't be added to a reef aquarium, IMO.

Chelation means that the copper is held by an organic carrier. A solution might be a mixture of free and chelated copper, and there are different types of organic materials used for chelation, some of which chelate more strongly than others.

I do not know in detail what Cuprex and Cuprex II are, and don't have any dosing recommendations other than what the manufacturer recommends.