API and seachem are all the shop carries, which sucks, but I guess I just make do. I figure I'm dosing 20g, which at .5ppm is 64 drops, 13~ (12.8) drops per .1ppm. I get a shade lighter than .5, and call it a day. I've done 5 six week QTs and it seems to have worked thus far. Salifert you say? I'm going to need more test solution, I think I'll give it a try. I'm ordering some new lights for the tank, hopefully they haven't shipped yet....
If not the Cu, what else do you think it could be? No one bothers him, and all he has been fed is frozen mysis, clam and mega-marine angel from the regals...