Well i started small to wasn't sure if i was even going to like the cost and up keep of a tank . Small tanks also don't take up much room ,to have a big tank you have to find a good place for it your house.So i started with a 55 but i would have proably started with a 90.To my surprise i love the hobby and have upgraded since then to a 300 and i'm more then happy now.It's really up to a person how much time and money they want to spend.