Pools with Crystal Water Monitor installed inline behave differently than poolside installations. When the pump is running, the water is circulating and the readings will be accurate. However, when the pump is not running, the readings can drift due to the stagnant water in the plumbing.
A good example of this would be a pool in Phoenix where the inline fixture is directly in the sun. When the pump stops circulating the water, the measured water temperature can rise dramatically. We've seen example of water in the plumbing reading above 120 °F.
In order to solve this issue, Crystal Water Monitor leverages your pump schedule, and pump detection (coming soon) to automatically detect when the pump is running. The system will then ignore readings that are taken when the pump is not running. You should be sure to verify that the schedule of your pump or pool controller is in-sync with the pump schedule entered in the Crystal Water Monitor app. If they are not in-sync the Crystal will ignore readings when it shouldn't and may accept readings when the pump is not running.
While Crystal believes the pump is not running, you will see an indicator banner in the app informing you that the readings and recommendations are based on the last reading taken while the pump was running.
Crystal recommends adding chemicals while the pump is running. If you need to add chemicals when the pump is not running, you should use your pump's controls to circulate the water for several hours. Crystal will update both readings and recommendations when the pump next runs.