my flagtail does not eat algae and prefer my rays slime coat so i sold it away
We had two that did the same and we had to re home but the rest are fine so I don't know if its just a habit some pick up
My biggest one is about 30cm
Strange story on this big boy... originally he would suck on the brown rays but left the black rays alone so.. we moved him to a tank with only black rays and problem solved, he is also fed cucumber every second day
About a year later we added two brown rays to same tank where they have been together now for over a year and he doesn't touch them