Coralife is one of the markets leading manufacturers of premium aquarium products. ; Coralifes hydrometer takes a true water sample at six inch depth. > Temperature – Easy to read and accurate, this specific gravity meter is designed to give corrected readings in warm water aquariums; Cora life is one of the markets leading manufacturers of premium aquarium products; Cora lifes Hydrometer takes a true water sample at six inch depth; Coralife is one of the markets leading manufacturers of premium aquarium products; Coralifes hydrometer takes a true water sample at six inch depth