Atleast 3 years old. When I got him he was about as big around, fins and all as a silver dollar and I had him in a 5g by himself with a snail. Then I moved him into a 10g, now hes in a 20g with only a few other fish, a frog and some snails. Him and my plecostomus are the only fish I have that have names, cause they are the biggest, lol.