Bad Blood Parrot

I have a 110 gallon tank that I set up about 4 weeks ago. I have all
juvenile fish in the tank, consisting of:

1 rainbow shark
3 tetras
4 angel fish
1 cory cat
1 blood parrot

The problem is, the parrot was nice to all this fish when the tank was
first set up, but as more time is passing the parrot is getting more
and more aggressive towards all the other fish, especially the angels.
There are lots of plants and caves in the tank so the fish have
plenty of places to hide. The parrot just chases the angels all the
time and every once and a while it will chase the cat and the shark.
Is there anything I can do to make the parrot behave in a less
aggrssive manor? Would adding more parrots help? I'm considering
adding 3 more parrots to try and raise either numbers so they may
leave all the other fish alone and establish a pecking order of there
own. My parrot is only about 1 inch long, so it's very small. A
friend of mine has a 220 gallon tank with about 5 or 6 5 inch parrots
and they all seem to get along peacefully with each other and all the
other fish in his tank. Any suggestions?

Thanks in advance!!