Fish are very territorial. You need to make sure that you have a large enough tank for all the fish to live together. Approximately 10 gallons per fish is a good amount, although the bigger the tanks, the more room they will have, and the less they will fight with each other. In nature, each fish will have it's own feed source, and shelter, but this is very difficult in a aquarium. Make sure you provide enough hiding spaces for all the fish to feel safe.
If this does not work, try adding a separator in your tank. This is a see through plexi-glass that you can put in to make one tank into two mini tanks. The fish will not be able to fight with each other through this.
If this also does not work, then you will need to remove one fish, the bully, from the tank, and get another tank or return it to the pet store.
If this does not work, try adding a separator in your tank. This is a see through plexi-glass that you can put in to make one tank into two mini tanks. The fish will not be able to fight with each other through this.
If this also does not work, then you will need to remove one fish, the bully, from the tank, and get another tank or return it to the pet store.