a little over a month ago for my clean up crew I purchased some margarita snails, cerith snails, mexican red leg hermit crabs ect..... so today when i was cleaning my tank i noticed atleast half of my snails were dead...so i asked my LFS what they though and they told me that hermit crabs kill snails for their shells....so I Need snails to eat my algae so should i get rid of the hermit crabs?? are they good for anything or do they just kill snails?? and another question since i'm so full of questions today, how many snails is a good amount for my tank?? I have a 29 gallon with 30 pounds of live rock. a guy told me 1 snail per pound. is that about right??