What are the dimensions of your tank? My made up rule about minimum tank size for solo cichlids is that the tank needs to be 3x as wide as the fish is long, and a couple inches taller and longer front to back than the fish.
It wouldn't be cruel or anything, but you could do it okay. Of course bigger is always better. The fish will let you know if they are not happy in the tank.
The tank is good front to back and heigth wise, but it probably won't be wide enough. Midas can hit 15", which is a really big push in a 36" tank. It'll be OK until it hits 10" or so though.