You definitely can but as you can guess they have their own requirements. For the sake of their health, you will have to keep seawater in the tank. Now, you may collect seawater or make it yourself, whatever the case- you will have to make sure the tank is compatible with the water. There are elements in seawater or saltwater that can harm glass or acrylic. Make sure the tank you are buying will receive no damage or will not decay because of the saltwater.