limitations on fish tank dimension

Hello! I have recently purchased a 125L tank, dimensions 81cm x 36cm x 50cm for a reef aquarium. I was wondering what stock would be my options? What are the can haves and can’t haves? I would absolutely love a butterfly but I understand that I probably don’t have the space. I’d also love a...

Hello Reef2Reef! I have a great place in my home to put a fish tank, but the dimensions would have to be 17 1/2 inches wide x 74 1/2 inches long. Any wider and the tank goes out too far into a walkway in the house. I have two questions: (1) Is there a minimum width (I heard the guys from...