If you seriously want to breed, people suggest buying around 6-8 types of a certain fish, to make sure you get a male and female, and let them pair off on their own. Since you have a 30G, that won't be an option. I responded to your other thread so i'll repeat this, you should get 3-4 of each type of cichlid, so 6-8 electric yellows and zebras.
There are quite a bit of different ways to encourage spawning in all fish here are some:
-Doing large and frequent water changes, around 50% everyday, or every other day till spawning. Then you can go back to normal ways.
-Feeding them a varity of foods, not the same stuff everyday. Like freezed-dried blood worms, live blood worms, meaty food, high-quality flake foods, pellets, and some veggies.
-Create tons of places which you expect the fish to spawn.
