I personally think 1 snail for every gallon really helps out. In a 30g I would go with 10 nassarius snails and 20 astrea/margurita snails. I also like having 1 hermit for every 2 gallons. Snails and hermits are a great addition because they help keep algae down, they eat leftover food that your fish don't eat, they stir up the sand bed, and if one of your animals die they will clean up the body in a matter of hours before the carcas can foul up your water.
3' fine sand bed 1x Orange Stripe Prawn shrimp goby, 1x sixline wrassemated pair of true percula clowns, 1x CBS shrimp, 2x peppermint shrimp, 1x pistol shrimp, 1x tiger tale cuke
, ~20+ snails, ~10+ hermits, 1xserpent star.
green Bubble coral, hammer coral (8 heads!) ,various Zoos,green finger leather, green star polpys ,shrooms
175w 10k MH
28w actinic 03
2x maxi jett 1200
Prizm skimmer (modded)
Hagen powerfilter(for running carbon 24/7)
nano arctica chiller