IME; it's not a matter of IF a dwarf angel is going to nip, but when and how badly. Sometimes it's something you can live with, especially if the fish is nipping at a mature colony that is large enough to hold it's own or even propagate faster & outpace the nipping. I've usually only had problems when a dwarf angel takes a liking to a small frag. :squigglemouth: For some reason, the yellow ones like Lemonpeel & Bicolor seem to be the worst.