For some reason every last turbo snail I've purchased recently have died. They seem fine for a week or so; then they stop moving - then die. I acclimate for 3-4 hours and I don't think that anything is bothering them. In the last 6 months I tried 6 from Deep-Reef, 6 from Scotts, 2 from Aquarium Designs and several from Old Town - all dead. I have plenty of algae. However, astreas (which everyone says are harder to keep) are thriving. Of the 15 I bought from Old Town, 14 are still going strong. Any ideas? I wonder if the local middle-man isn't acclimating them well.