Get accurate results for your saltwater aquarium with our simple handheld colorimeter. Our ultra low range phosphorus colorimeter brings you more precise technology from your typical chemical test kit. Standard test kits have limited accuracy since they rely on the user to match colors. Our handheld colorimeter makes your life easier by eliminating color matching and providing you a direct saltwater phosphorus result. - Take our portable handheld colorimeter anywhere. - Simple, one-button design makes getting your results easy. - Improve your technology and upgrade from your standard test kit.