it is 30" across, but how wide is it? At 30", a full grown bichir can swim only twice it's body length, and can't fully turn around without hitting it's head or tail on the back of your tank. That is like a six foot man being confined to a jail cell 12 feet long by 5 feet wide. I would suggest you invest in a bigger tank than getting a bichir now. As cool as they are, they grow too fast. I would even forget my suggestion of a 55 and go for a 75.