I have 6 Lyretail Anthias that have been in my 210 for about 5 months now. However, I can't seem to fatten them up. All other fish (Power Blue, Flame Angel, 7 Green Chromis, 2 False Perc) are all fat and happy. I feed once a day, 2 cubes of various mix (Angel and Butterfly food, H2O fish reef #1...