I have a 5 inch rd in a 29 gallon.It was in a 75 gallon with a 6 inch oscar but the rd was to aggressive.So i put it back in the 75 gallon because my mom made me.Time after time i tried introducing it to the 75 gallon but eventually i had to remove my reddevil from the 75.Would it be happy in the 75.It is a female rd.I thought about getting ita 46 gallon bowlfront or a 40 gallon would it be alright.Give some advice............or is there a way i could keep the rd and oscar together.I heard u could reduce aggression by rearanging the tank but help me out.