Mine has laid eggs about 10-15 times but I have never gotten fry beyond 3cm, mostly because im lazy.
My tank is 600 gallon, I keep the water kind of cold because it looks like that trigger breeding, I have a good amount of oxygien in the tank. Thats the tips I can give you.
And one more thing,,, Keep them by themselves, I have noticed that thet dont breed if something is bothering them