No matter the size of your aquarium, Instant Ocean® sea salts and water care products offer the smartest, easiest way to bring the ocean home. Our scientifically formulated sea salts are used exclusively by many of the leading large-scale aquariums and research facilities across the country. Accurate, reliable water test equipment is a vital part of maintaining a healthy, successful marine aquarium. Easy to read and simple to operate, Instant Ocean® Hydrometer delivers precise, full-range salinity and specific gravity readings. Ideal for use in water temperatures of 68 degrees to 85 degrees, Instant Ocean Hydrometer provides easy-fill convenience – no wet hands! With an extra-wide stabilizer base, this easy-read tool has a two-color scale with a safe zone for simple results. To use, dunk the hydrometer in your aquarium to fill with water. Dislodge air bubbles by tapping gently. Place the tool on a level surface to read specific gravity. For most marine aquariums, recommended specific gravity is 1.020 to 1.026. Instant Ocean offers a full line of products, including sea salt, water treatments, test kits and accessories, to make sure your saltwater aquarium remains vibrant and healthy. MARINE HYDROMETER: Tests salinity and specific gravity in marine aquariums to help maintain a healthy tank. ACCURATE: Precise, full-range readings – accurate to +/- 0.001. READY TO USE: Simply dunk in aquarium to fill with water, then set on level surface to read. EASY TO READ: Clearly marked to show results. USE WITH INSTANT OCEAN® SEA SALT: The industry standard for quality, consistency and value for more than 40 years.