I have a hybrid stingray that’s about 1 foot in diameter and I was wondering what cichlid species can I keep with it. In the tank I have a black arowana, 2 bichirs, 1 gar, and a large geophagus. The tank is 270 gallons.
Sounds like that tank is pretty crowded already. Sure you want to add more? I avoid most cichlids as ray tank mates. The ones that can hold their own with rays are likely to pick on the ray.
Agree with big fish nut. You need to think how big these fish are gonna get. The ray, Arowana and gar will probably out grow a 270. Plus the Birchers will get pretty big too. I’d leave it at that.
Assuming you have the tank space, I'd recommend Geophagus species, specifically G.Winemilleri if you can find them. I had a school of them with a pair of BD/Leos for years in a 300 gallon tank. See: