it depends on the type I say. I had a leapord sail fin about 12"+ in a 315g that left his mark in the acrylic. That wa the first time & only time so far. I have several in acrylic displays now without much problems but I do want to put a 6" Vampire L29 in one of the displays with many other Plecos but worried about this guy sinking his teeth in the acrylic & aggression with the others?
Give them plenty of hiding spots, wood etc. would help keep him of the sides of the tank.
me