i believe the main negative thing about urchins is that they eat coraline algae. I do not have one nor want one...that is what i believe is why many people do not have them.
coraline, and sometimest they coraline on the power chords, and when they bite into the cord
they can fry the whole shebang
plus they can topple rocks and corals quiter easily
I also wanted to get one until I found out that they eat the coraline, in the process grind up your live rock into powder. <img src="graemlins//eek.gif" border="0" alt="[eek]" />
