I have had them for about a year. They were maybe 1.5 inches. Those are both just estimates though. My memory is horrible. :lolspin:
My only inverts are some hermit crabs and 2 peppermint shrimp.
I was worried about the shrimps at first, but they seemed fine. It has been a few months since I've seen them though, so it IS possible that the flames have eaten them(!) (I only ever saw them after dark- I'll let you know if I see them again
)
The aggression was a bit rough in the beginning. To the point where I actually tried to trap one of them (but I failed)
The aggressor didn't chase the other one constantly, but every time he saw him he would attack instantly and stay on him for few seconds. It looked bad.
Eventually though, the attacks started getting less ferocious and after a while it was just a "scare"; no actual biting or anything. At that point, the weaker hawk started spending more and more time out perching in the open. And then one day I saw them perching together. It all just happened super gradual over a few months.
Tank is 100g (40x30x20) with a lot of spaces for hiding. Not sure how it would have turned out in a smaller tank.
Added a pic for reference (and ofc, on that one they are NOT together, but... whatever. Maybe I can record a quick vid of them later on
)
Good luck!