how many keep urchins and what kind


Reef enthusiast
curious about what kind are good to have i like inverts also i got starfish, cucumbers, shrimps, conchs, clams, but no urchins are they safe to keep i know some are poisonous and some knock over rocks and can damage corals but it seems some people keep them and i was just curious which ones were good ones
Im not sure on all urchins, but a friend of mine has a pincushion urchin in his reef tank. Its really a pain. it picks up hermits, snails, frags, anything small, and moves it wherever... he likes it though. Only sometimes he loses frags for a week or so before he finds them again. And, Hes lost probably 2 frags at least of zoanthids from this.
i have a colored or tuxido urchin he seem to be good so far been in there for 1 week only moves at night as soon as i turn the lights off fun to watch and hasnt bothered anything yet also hides pretty good in the rock during the day the sites i read on it says reef safe with caution some may eat some soft corals i have a mushroom and open brain and hasnt bothered them at all
a long spined urchin is best for a reef tank, as they are gentle in moving around your coral and won't bulldoze or pick your coral up.

pin cushions and royal urchins will pick things up and move them around. But are reef safe.

Pencil urchins will eat your coral I would avoid these.

something to keep in mind is that all urchins eat algae which includes coraline algae..