I have a 29 gallon reef aquarium. I currently have 1 ocellaris clownfish, 1 flame angel, and 1 royal gramma. the clownfish, and angel were my first two fish, added same time, and got along since day 1 never an issue, a few weeks later I introduced the royal gramma. he is tiny maybe 1 inch or so. The clownfish and angel chased him around for about 5 mins, until he found a cave to sleep the night. The next morning he was out and about and the angel and clown had no issue with him as I had hoped. I seem atm the have a peaceful aquarium and I would like to keep it peaceful for my 4th and last fish I had some options, and would like some feedback. First option was a firefish, I hear they are peaceful. My only concern is he would be a cave dweller as is they royal gramma, and I know grammas can be protective of their caves. I have about 6-7 different holes, and caves so hopefully won't be an issue. Option 2 get a second smaller ocellaris clownfish, but I have questions about this, does a paired set of clownfish act any differently, become more aggressive etc. The angelfish and the clown swim around together all day and the gramma stays close to the rocks but also ventures about. I want to keep as peaceful a setup as possible, so with these two options what do you all suggest, and possibly can you suggest other fish I may have not considered.