Designed for reef hobbyists who demand precision, the Tropic Marin® High Precision Hydrometer provides reliable readings of specific gravity in your saltwater aquarium. With a maximum deviation of just 0.001 and a resolution of 0.0001, this tool ensures you maintain optimal salinity levels for coral and marine life health. How to Use: Fill the Measuring Cylinder Use up to 400 ml of saltwater at 25 °C / 77 °F—temperature is critical, as specific gravity is temperature-dependent. Insert the Hydrometer Ensure the hydrometer is dry and clean, then gently place it into the water so it floats freely without touching the sides. Take the Reading Read the value on the blue scale at the water surface level—not the meniscus (the curved edge of the water line). Clean After Use Rinse both the cylinder and hydrometer thoroughly with fresh tap or RO water to prevent salt buildup that could affect accuracy. Specifications: Scale Range: 1.021 to 1.031 Resolution: 0.0001 Maximum Deviation: ±0.001 at 25 °C / 77 °F Recommended Reef Range: 1.025 to 1.027
