I dont know how long you have been keeping fish but you show that you have some experience with other cichlids. i dont think you should worry about being flamed because you didnt know in advance that on a scale of 1 to 10 relative to the fish you have a red devils aggression can be a 15. they can be relentless in taking on any size fish. The red devil is the terminator of the cichlid hobby in any tank less than about double your 125 with the same type fish.As mentioned already the can be geat as solo (but also possible to keep in pairs in the right setting).i give you credit for posting your problem...plus it seems you didnt have any fatalities yet..follow the advice already given in those first 4 replies but also you should get a divider in the short run to prevent any losses until you decide what you want to do .... good luck.
