I don't know, I think it more prudent to get a fish you know you can house at adult size. I don't buy farlowellas and keep them in a 10 gallon until they get 'large enough' in my mind to warrant setting up a larger tank. Get the largest tank you can first and house the fish accordingly. Would you say a person who keeps an oscar in a 10 gallon tank until he gets too large to move is being smart with his money or selfish with his wants over the fish's needs?