I'm thinking of getting discus in my 150 gallon but I don't know if I can with my fish already in it. Here's what fish I have currently. 1 ornate bichir 7" one Delhezi bichir 3-4" one black ghost knife 4-5" one African brown knife 4-5" a sunshine pleco 4-5" one pictus catfish 5" let me know your opinions please.