Hi Dave, welcome to the forum.
Everything I have read about breeding keyholes says this:
"They can be one easier cichlids to breed, and have even bred in community tanks. Several young should be placed in your tank and allowed to pair off. They are open breeders, up to 300 eggs are deposited on a cleaned stone. The eggs are cared for by both parents, who will fan them with fresh water and pick out the unfertilized eggs. Many times a pair will eat their first brood, but they will spawn again in a matter of days. You can remove the eggs after they are laid if this continues and raise them in a separate tank.. The fry hatch after 3-5 days and are free-swimming several days later. Start feeding with roftiers and baby brine shrimp. The parents may continue their care for the fry for up to six months."
but I can't find the info as far as to what age breeding will begin. Anybody know?