I have a 4.5" TL SAE
and he is constantly going to town on the algae growing on my driftwood. Heck he even goes for the algae on the glass, but they are obviously not suckers, literally. I bought him at 2" approximately 8 months ago; they more than double in size in no time. And he's fat, to boot. He's not aggressive at all, but they can be if housed with another of its kind, especially in a tank less than 40g.