Penn-Plax Deco-Replicas Sand & Seashell Lighthouse Aquarium Ornament. This piece is accented with a blue trim, mini decorative windows and entries, an open star cutout, and 2 large entrance swim-throughs. The material is safe for both freshwater and saltwater aquariums. With a finely constructed base, you don’t need to worry about the Lighthouse floating around once you place it underwater. Before placing into your tank, or as you perform regular cleaning and maintenance, simply wipe down and rinse off the ornament with warm water. Never use soap, as the residual soap particles can harm your fish. The Lighthouse measures overall at 3.5” (Diameter) x 8.3” (Height). The 2 large entrance swim-throughs measure 2” (W) x 2.5” (H) and 1.5” (W) x 2.25” (H). Makes a great decoration piece for parties, weddings, beach houses, nautical themed rooms, or the bedroom of an ocean loving child who’s into all things aquatic.