Currently my Gibbiceps (FINALLY I KNOW WHAT TO CALL IT) is only 3 or 4 inches long, i have had it with my two other plecos (common 7inches, and chocolate 3 inches) in my 20 gallon (75 liters) tank. I just transfered them to my bigger tank, 40 gallons (151 liters). They seem to enjoy the extra room, but in the 20 gallon tank they seemed to be fine. THANKS A BUNCH.