I have 4 F1 lyonsi, and 4 tomocichla sieblodii, the sieboldii are about 3" and the lyonsi are between 5-6". The sieboldii had a brood they were raising when I purchased them. And the lyonsi have spawned once before but ate the eggs. So I'm sure I have at least one male and one female of each. Currently they are growing out in seperate tanks. I would like to add them together in a 5' 120 gallon tank. With both species getting around 10" at adulthood, I would think they would be ok. But before I do things I like to ask around on the forums to see what others think. So what do you think? Does it seem plausable to you? Thanks for shareing opinions on this.