I had one of these little guys back when I had my 175 gallon and I loved him. Now I'm doing my research for stocking my 14 gallon nano and I thought of him again because I remembered that they stayed small. However, even though they only get 3" maximum, I keep seeing that they need 30-55 gallons at minimum. What's the reason for that? None of the sites I'm looking at give any explanation.