diff --git a/src/Controller/MonitoringApiController.php b/src/Controller/MonitoringApiController.php
index 7ae4462..f5b3eda 100644
--- a/src/Controller/MonitoringApiController.php
+++ b/src/Controller/MonitoringApiController.php
@@ -144,9 +144,9 @@ class MonitoringApiController extends AbstractController
 
             if ($lightTime >= $lightOnAt && $lightTime <= $lightOffAt) {
                 $lightOn['data'][] = 10;
-                $lightOff['data'][] = 0;
+                $lightOff['data'][] = null;
             } else {
-                $lightOn['data'][] = 0;
+                $lightOn['data'][] = null;
                 $lightOff['data'][] = 10;
             }
         }