I really love my pistol shrimp (I have two now). Beware though if your rock is not on the bottom with sand pored in around it the destructuion will be extensive!! If you are setting up a new tank though you could take the neccesary precautions and have a really interesting creature to watch. My system is only aout a month old but all the rock, sand critters have been in my old 55 for four years.