I have the California Round Rays and they like cooler water temps like in the mid 60s would be ideal, but mine are in the upper 60s (68-69) cause the pool and pond are on the basement concrete so you dont have to many options as far as fish. I would like to get a Calico Bass or 2 but other than that I dont really want more. If you get the warmer water Rays like the Yellow Ray, Atlantic and some of the Blue Spot Rays (if you can keep it alive) then you can put some Tangs, Wrasses and other peaceful fish that wont fit in the Rays mouth. Mine ate a 6 line Wrasse that was 2 1/2" and a Neon Goby that was supossed to clean it. I had a Sailfin Tang with mine for a while before I droped the temp. down. You can not have Puffers or Triggers at all with the Rays. Also you could go with Groupers if you want. They are very interactive with us, like begging for food, allowing us to pet them but dont know if they like it or maybe they know they are getting a treat. They really make a nice water pet!