I had CC spawn in a 2/3 acre pond. They utilized either 2 or 3 7 gallon buckets laid on their sides or a 70-ish galllon watering trough placed upside down with a hole in one end. Although I caught a few 8-9'' CC from the spawn, I don't think any of them made it to adulthood.
Absent predators, its easy to get too many CC from reproduction; with predators, its very hard to get just the right number. Fortunately advanced CC fingerlings are both readily available about about the cheapest fish to buy in any size.