Seaview seals your background to your aquarium, eliminating the rtefraction of light behind the glass, resulting in a flawless, illuminated, 3D view of your background from any angle. Maintain a flawless and vivid view of your aquarium background. Seaview Gel creates a proper seal to eliminate bubbles, ripples and light refraction that makes mylar aquarium backgrounds appear faded or fouled. Easy to reply and removable for convenient background changes. Completely nontoxic - use SeaView with freshwater or saltwater aquariums, whether glass or acrylic. 1 oz SeaView gel treats up to a 75 gallon aquarium.