I think for now I'll just let them grow out with the parents in the 20. As I mentioned I think this will be more of just a treat thing, all my fish are already feeding fine on pellets and bloodworms so I'm not worried about NEEDING to feed them live fish. If in the future I can afford a larger tank to dedicate to this I might get like a 40long or something and put two dividers in it for 3 pairs of convicts then use the current 20 as a growout for the fry.
But thats all in the future
For now I'd just like to experiment with one pair of convicts and let the fry grow as quickly as they will in the parents tank. Just gotta figure out what to do with the pleco.
But thats all in the future