Did you get them from the ocean in New Hampshire? If so, those are totally different species than the tropical animals that live in your tank. I wouldn't add anything to my tank that I collected myself -- you never know what kind of diseases or pests it could be carrying, or if it is even reef-safe and will be safe around your animals. Any algae you find is not going to be the same type of algae that grows in tangs' habitats -- the tropics. Any snails you collect off the frigid waters of New England will boil very quickly in a 78-degree reef tank. Not to mention all the pollution off the eastern coast.