Trying to figure out the picture deal. Can't wait to show off my fish and some of my plants. Don't see black edges, just seems to have become more... transparent then he was and fins are not as gorgeous as they were. Will keep an eye on it, but if there is any fin/tail loss, you wouldn't give any medication? Just water? I've been doing PWC's every couple of days, test daily and slightest color change from zero levels of ammonia and nitrites mandate PWC's, so it's not that. About filter carbon... Well first day of treatment it didn't click in my head what that meant in the I structuring on med bottle. Then I got to thinking about it and started reading on Internet and then sliced open the cartridges spilled the carbon out and did the 3 days of med from that point on, so I think they have got it. The medicine I used is what my lfs "betta lady" recommended Mardel Quick Cure, on the bottle for ingredients it does not list copper (tho had snail in one of the affected tanks and took him out just in case, but the shrimp... Good luck catching them! It has Malachite green and Formalin are the ingredients of Quick Cure. I'm still seeing the "gold dust on couple of fish but they act normal so at this point I'll try the no lights strategy and just watch them for few days. See what happens. Hope I answered all of your questions, should have quoted, that way I would have been able to refer back to your post. Thank you so much for taking your time trying to help me