I have a 30 gal. tank that is not quite 3 months old. It was cycled with about 40 lbs. live sand, 15 pounds of live rock and cycled in about 3 weeks. Now it houses a peppermint shrimp, a blue damsel, a scooter blenny, about 12 hermits, 5 turbo snails, a small snail that just appeared one day...