I have a RD/Midas (from petsmart) in my 300gal, 8x2x2.5H, and he killed my FH that was about 2-3 inches smaller than him about 9-12 months ago. The RD/Midas was around 12inches at the time. There are also good size SDs, Large Blk Aro, pike, sevs, etc. For a while he was picking on all the fish, but worried about my Blk Aro because he is very docile. I think because of the cooler weather and my tank not getting as warm he has calmed down, I also put my 7-8 FH back in the tank as he was terrorizing P-bass and a Jardini Aro in another tank.
I would suggest:
Lowering the temp of the tank to 78 if you haven't done so already.
Getting some target fish, good size SDs or large Giant Danios to take some of the beating as well as distract the RD/Midas, possible 5-6 of either one.
I would suggest:
Lowering the temp of the tank to 78 if you haven't done so already.
Getting some target fish, good size SDs or large Giant Danios to take some of the beating as well as distract the RD/Midas, possible 5-6 of either one.