There is a lot of good info on raising fish on the NANFA website and forum. I have bred a lot of different native fish in aquariums over the years and can say GSH grow super fast. Something in the neighborhood of a stock tank like you said with a reasonable sized filter to clean and aerate the water should work well. Make sure the inflow into the filter isn't too strong or you'll suck the fry up into it. Make sure you keep the stock tank in a shady area and put a cover on it, like the mesh you mentioned for a screen room. Within a month if you feed them well, those little GSH fry will be .5 to 1 inch... When breeding most of the Cyprinid species, I usually just used finely ground goldfish flakes and that seemed to work fine for them. The difference between fry and .5 inch GSH is night and day in their ability to avoid predation...
