yeah i would just go with one, and i would def go with a nice male umbee!! if it doesn't work oh well, an umbee pair in a separate tank would be AWESOME as well, and if its a tank bred frontosa then water parameters arent as important but yeah i agree when everyone gets big the frontosa may end up being the whipping boy of the tank, i actually have one in my tank right now with my Sa/Ca and he actually holds his own but they are all 4in or under so im sure it most likely wont work in the long run