Yup, they're real aquariums!
George and Steven Lo of Aqua Forest Aquarium in San Francisco make aquariums - but not just any ol' fish tank. Their creations of "Nature Aquariums" are simply stunning: real plants are used to create a natural (albeit underwater) diorama.
Link [website has self-starting background music] | Portfolio - via Apartment Therapy San Francisco
If you have a snail infestation, it's quite difficult to get rid of. For mild infestation you can float a piece of lettuce - snails will flock to the lettuce. Simply float new lettuce leaf every few hours or every day until you don't have snail anymore.