One of my female discus is laying the egg so that I put one discus I think this is a male with the female together. When the female lays second time the male eat all the egg instead of fertilized them. Female lay one egg and the male eat one egg. Why? Will it become parents. Should I wait or not? Can i paired the female with another one?
The one discus you put in could be a female.
If it is a male, then he must be not ready or inexperience.
Put a few adult fish together and allow them to pair up by themselves.
They prefer to select their own partner.