Valentini puffer attacking clownfish

Ok. So ive been a marine hobbiest for only 4 months.I have done alot of research about this hobby. I Have a Valentini Puffer fish. chocolate chip starfish, Two Percula clownfish, three crabs, and a few turbo snails. Just recently i had velvet in my tank, and it killed my first clownfish...(my puffer got along with) A month later i was able to purchase a pair of clownfish. They were doing fine in my tank for about a week, when my puffer began to pick away at them...he doesnt pick at the snails very much and leaves my starfish alone. I didnt have this problem before, and i havent heard of anyone else having this problem either. Just wondering if anyone has heard of this or if i am looking at possibly removing the clowns from my tank ( can not part with my puffer). My puffer has a very good diet that consists of bloodworms, krill, brine, flake foods ext. Any suggestions help. Thankyou

 

re arrange rock work?

 

I just did a few days ago. I originally had a few pieces of live rock lying around in random places of the tank. ive been slowly adding more rock to my tank. and i just started stacking the rocks. Puffer seems to like it. but my clowns just stay in theyre sand bed all day.