Hello, I have a 75 gallon tank with 3 dinosaur birchirs(7in), An needlenose gar (10in), a catfish, angelfish, and pleco(6in), And 2 Jack Dempsey's(6in). I just bought th 2 jack dempsey's and think there 2 males. I read online that if u lower the water temp. it reduces fish aggression so I did that. My jack dempseys hide and was wondering how to get them out so i can see them, If my tank is not gonna work, and any general info I should know about jack dempseys. Thanks Alex