Start off slow with the snails and hermits - don't thru 50 into a 55 gal at once - odds are there isn't enuff food for all of them anyways. Also multiple species of hermits don't always get along. I started with 3 Red legs 10 blue legs and a scarlet, then went all out on Halloween Hermits - end result red legs killed off the others.
Big ole' Turbo snails are cool - I luv'em but same problem - need food or will perish. These guys can knock down corals as well - mine have at least.
As for seaweed - your grocery store might sell Nori sheets same as some seaweed sheets sold ar pet/fish stores.
