Aquatopia Marine Hydrometer - Professional Saltwater Refractometer for Aquariums, Fish Tanks & Saltwater Testing | Accurate Salinity Measurement Tool for Marine Life, Reef Tanks & Aquatic Enthusiasts

The Aquatopia Marine Hydrometer ia a pre-calibrated, wide-range specific gravity meter. It is self-levelling. Your hands stay dry. The Marine Hydrometer takes a true water sample at 15cm depth, thus avoiding inaccurate surface samples. It is easy to read and accurate to approximately +/- 0.0001 specific gravity units.