hey i currently have a ck and a lime shovelnose in a 4x2x2 growout and both are currently around 5-6 inches my question is could i add a bgk i am aware that the ck will need a larger tank. also once the bgk has grown abit could i add it to my 72"x18"x18" tank with my 3 oscars giraffe cat and my ornate?