I just went on vacation for two weeks, during this time my dwarf lion died under the care of the house keeper. The tank is empty except for a small serpent star an a plaugue of emerald green algae. Because my family plans to travel in the future I need to get a fish that is not carnivorous (I think the death was food related because the house keeper said the water perameters were good). The idea I had was to get a yellow tang and a large quantity of crustaceans. The problem is that I am not sure that it will fit in my 55 gallon. So I am wondering if it doesn't fit what colorful fish would fill that sort of niche? Thank you.