Clowns turning very aggressive to chromis

[_reefNE_]

I have a JBJ45 with 2 clowns, 1 chromis, 2 firefish, one clown goby, one cardinal fish, cleaner shrimp, emerald crab and CUC.
I've had them together for at least 6 months. They've been fine the whole time. However, now the clowns are picking on him NON STOP.
I feed brine shrimp daily so everyone is well fed. Water parameters are all in range. undetectable nitrates and phosphates.
I do not have an anemone for the clowns as I'm afraid of it splitting over and over and taking over the tank.

I'd appreciate any thoughts on why this may be happening and any potential solutions.

 

[1Matthew]

Clowns are known to be a bit aggressive. In my case my clown became the dominant fish over a tang! He even bites my finger when I clean the tank.