A 10-gallon is fine for a breeding trio and then some fry. I separate my breeding pairs (of L-144's) into 10-gallon tanks without issue when I want to keep some fry but you must keep on top of the water as things could go badly really fast in a smaller tank. I had major issues with a couple of my tanks last month after I returned from an extended trip, but that is another story :irked: . I generally select one male and two females for breeding my L-144's and I have even had both females deposit their eggs for the male. I put the females back after they have set some eggs and then I put the male back into their larger tanks when their job with the fry is done, and then continue to raise the fry in the 10-gallon tank. That is what works best for me but there are a lot of ways that other folks raise their fish. It all comes down to what works for you that is best.