So usually when i get a new fish i do research on it but since i had an empty tank i just bought the fish that i liked the most and it was the undulated trigger. I should have saw the signs the fact that he was in a tank by himself or the actual sign that said extra extra aggressive. I love the fish but i wanted one more fish for my tank and after looking at compatability charts and reading up on him i found out that is easier said then done. The guy at the pet store told me i should try the panther grouper with him. I was sceptical because of the things ive read about the undulated trigger but i went for it. I watched the fish like a hawk for three hours and they were fine, i even turned off the light and watched them for a little bit longer to see if he would attack him at night but nothing. I came home from work today and the trigger definitely got a few chunks out of his fins while i was gone. So now the reason why im here is to ask what i should do. Should i leave the grouper in the tank? and hope its just some domanance this is my tank beef with a new fish that will go away with time. Or should i listen to the stuff i read online and bring the grouper back to the store before my trigger kills it? I really really like the trigger but i want one more fish in the tank with him so should i try a different fish or just accept that he will just attack and murder everything i put in with him. Helppp lol