A common hatchery technique is to keep broodfish captive in a controlled, confined environment until the hatchery people are ready for them to spawn. I think you can hold them for another two or three weeks and ensure they eat the food and develop their eggs. Once you turn them loose, there is no guarantee they will actively seek you for food. Plus, if you back them up a couple of weeks, you will have more natural food for them, too. I think they will be more likely to spawn at the same time if you keep them up a little longer.
Teach a man to grow fish... He can teach to catch fish...
