Following up with the groupers, I would have to agree that 120 is a bit small for the regularly available ones like Panther and miniatus because they are very aggressive. However, if you're set on getting one, try to get your hands on a honeycomb grouper. I used to have one in my 150 and he was fine. They usually get about 9" long and max out around 1'. Hope this helps
also, try not to get lionfish with triggers because the triggers will tear their fins apart.
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