i thought that bala sharks get too big for a 135 gallon tank. Or was i misinformed¿?

bala's get to about a foot long but they dont have the volume of an oscar. They do need lots of swimming space

Just an update to all who responded. It has been close to a year and the 2 oscars have formed a pair and are about 11 inches now. The red devil is about 10 inches and is one nasty fish. the dempsey unfortunatly was getting beaten up pretty good so I upgraded the 38 to a 75 gallon and he is now fine in that tank. The two oscars protect each other and do not seem to quarrel with the devil to often as long as the stay on there side. The balas are almost 12 inches and are fine. The pleco gets harrassed from time to time. I have bought another fish called a Mystus leucophasis,it is a black upside down catfish about 8-9 inches now and is the only fish in the tank able to deal with the devil although it only comes out with low or no light.

Is your Red Devil a Male or Female?

Reason why I ask is because my Dad raised Oscars and Red Devils.

He always put a Female Red Devil in the tank with the Oscars but smaller than the Oscars and never had any problems cause the female is less of a agressive fish.

The devil is a male and all were about 2-3 inches when they went ito the tank. The oscars are fine as long as they stay in there area, when they do roam the midas is quick to put them back. Any other fish I have tried was attacked constantly and I have since given up as to adding fish to this tank.