KH keeper is a smart KH measuring instrument that uses high-quality components with an accuracy of +/- 0.01 dKh. The automatic measurement can be set in the range every hour to... KH keeper is a smart KH measuring instrument that uses high-quality components with an accuracy of +/- 0.01 dKh. The automatic measurement can be set in the range to test every hour to every 12 hours per day. The KH keeper is a standalone KH monitor that tests water samples directly from your aquarium to test the KH. If the carb reading fluctuates too much between readings, KH Keeper will repeat the test. If the result is confirmed, the device will send you an alert via the Smart Reef app available for both iOS and Android! The 'waste' water can be pumped back into the aquarium, but you can also collect it in a bottle and throw it away later KH Keeper is easy to set up and use with a user friendly environment and configuration.