I have one, But he must be the exception to all of these rules lol. He is in a 150 gallon tank with many different cichlids (oscar, jaguar, Jack dempsey, convict, firemouth, young flowerhorn) and is by far the most Bad *** fish in there! Anytime any of the cichlids mess with him, he rips them apart. He is so much faster and better at maneuvering around these fish. He is extremely hardy. One time I was moving him to a new tank and during the process he jumped out of the five gallon bucket(unknowingly) I filled the 55 gallon tank and put the other fish in and then realized he was not in their. I went back downstairs and found him on the ground not breathing...placed him into the water, said a prayer, and he lived. The total time he was out of the water was anywhere from 30-45 minutes, and he lived and is still going strong. Very neat fish. He eats shrimp, pellets, feeders, crickets, and ghost shrimp.
As of right now he is a 150 gallon 6' long tank. The filtration I have going is two fluval 403 filters. and two powerheads pushing current around. He can be territorial at times. water is about 80 degrees. I have never checked my ph before on any of my tanks, so I do not know about that aspect.