I agree.. they are very much like Cichlids in respects to territories ect. the problem lies in long-term housing. Max sizes are very different.. why mixing the 2 largest species w/ one of the smallest species is more of a make-up for disaster. I would also reccomend adding 2 new ones at the same time, and shuffling around the current decor when you do, or waiting and adding all 3 at once. Just as you would for Cichlids. I've had alot of luck with this method. and when my guys get overly aggressive I will switch things around to keep their focus on something else for awhile. My first fire eel killed it's "buddy".. so I went back and got 2 more and added them. The current fire had a hard time then singling out either of the new fish to focus it's aggression on and this has been working well w/ everyone for going on a year very soon. The only other problem lies w/ these fish tending to succumb to stress fairly readily. I'de be very hesitant to take away hiding spots, as this will increase stress levels and open the fish up to bacterial infections ect. a few small PVC pipes work very well for the species I've kept, make cleaning easy, and allowing fairly easy viewing to make sure no ones overly hurt or aggitated.