The only solution to keep the fish from mating is male only, but in my experience there are a few things you can do to keep the tank from overpopulation (without just scooping out fish and selling/disposing of them).
Having catfish (pictus and other varieties) in the tank helps with keeping juvenile populations down. They are great hunters, especially when they have not been fed in a while. This leads to my second suggestion. Any time I want juveniles to be culled, I just don't feed the tank for a few days (maybe even a week or two). As the fish become hungry they look for other food sources - the juveniles. Doing this, my tanks are basically juvenile free in a matter of days.