Hi guys, I am really new here. I have a bicolor angel that developed a dark blue (same color as its back side) streak by its dorsal fin. I have never seen any bicolor like this before. Usually their yellow parts are quite yellow without any blue in them. I think he might be sick. But I am not sure since he's been like this for almost 3 months now, is eating quite well, and seem to be acting normal. Also my water parameters are all 0 (nitrate, nitrite, and ammonia), and the PH is at around 8.2. So it doesn't seem to be water quality related. I am a little apprehensive in trying to medicate him again, because 2 weeks ago I added that microbe-lift Artemis and Herbtana product to the tank, and even though it said that it was safe to be used with invertebrates, it killed all of my snails. I've attached a picture. Has anyone seen this before?...
