I attempted to keep a 2.3 grouping in a 75gallon tall aquarium. It didn't go well, despite being heavily planted. The larger male constanly flashed warning colors to the smaller male. In turn the small male most of the time looked more like a female by his patterning. That went on for a week or two before I seperated them. The small male seemed afraid to move much and looked as if he was loosing weight.