Hello, A couple weeks ago i bought a cherub angelfish. He had ick but i treated it in the tank, all gone, no problem. For the past couple of days I've noticed a slight discoloration on his sides. Its like a metallic green. He eats well and is constantly swimming around picking at rocks. tank specs, biocube 29 2 clownfish 1 bangaii cardinal 1 cherub angelfish thanks.