i use nessarius snails, several different kinda of conchs, cucumber, cherry clams, cerith snails and a few other small things. but without a doubt the most benificial cleaner of my sand bed is the cucumber and the nessarius snails. the cherry clams also do a great job and are super cheap. pick them up at your local fish market or grocery store, just make sure they are alive and wet when you get them. then put them in seperate conatainers and let them acclimate for awhile and soon they will start to open up. once they have opened empty the water and replace with new tank water for about 15-30 min or so then drop them in your tank. real cheap and a great addition to any reef tank with a deep sand bed!