I have a 55 gallon tank with 2 young archer fish (I know its not a brackish tank, they'll be fine), and what I believe to be a small brittlenose pleco. I want to get at least one more archer fish, and I definitely want a fire eel. Can someone suggest a schooling species that wont destroy everything and also wont be destroyed by the more predatory archers or fire eel? I would love Exodons but I fear the buck tooth terrors would be to hard on everything once they reached their full size. Any suggestions?