I’m not trying to ignore it, but no one can give a straight answer that it won’t work. Yes many people have tried to keep oscars in 29 gallon tanks, so you can easily see that it won’t work, but I can find anything at all about red Texas and jack Dempsey’s in the same tank. So like I said before I’ll try it, and keep an eye on the tank, then if it works great! If not then I’ll take the proper action and rehome the fish, or return the fish, then I’ll make a post about it and tell others that no it won’t work.