History works only when the device is connected to the Smart reef system. If your device has not been connected or lost connection due to an issue with the Internet connection or power outage, you won’t be able to see your history.
If you can’t see the history of the dKH results and the Internet connection is available, please make sure that the taken measures are within 5-15dKH limits.
The device won’t upload results outside of these limits to the system and they won’t appear in the history chart.