oscar fish and more!

Question
Hi, i know own a beautifull cichlid aquarium which is 37 gallonds.In it i have a couple of convicts and some younger ones and a few other cichlids like a green terror, another yellow one and 2 plecostomus.But i really would like to add 4 more new fish here they are, one or 2 oscar fish(small-medium size) an irridesant shark and any other fish which may go along with this type ,like maby like a pictus catfish or if possible a freshwater puffer fish but i would really enjoy a pair if oscar fish, please help!!!!

Answer
Dear Michael,
Thanks for your letter. I don't have the technical expertise to tell you if all those fish are compatible. You might want to take it slow unless you are already a very experienced aquarium keeper. If you're new at the hobby, let me warn you about the horror story that can unfold in the tank when the fish start to die one by one. Every veteran aquarium owner has been through it. The leading cause of fish loss is overfeeding, so be sure to avoid doing it. For many of us, it took years to learn that one simple thing. My page for the aquarium hobby is:
http://steamboats.com/aquarium.html
If you've been keeping aquariums this all your life, then pardon my comments. Do what your intuition tells you - 37 gallons is a pretty good size.
Sincerely,
Nori