diff --git a/src/controllers/tanksController.js b/src/controllers/tanksController.js
index 30cdffc9..64218f80 100644
--- a/src/controllers/tanksController.js
+++ b/src/controllers/tanksController.js
@@ -6147,9 +6147,23 @@ async function processIotData(hw_Id, data) {
       const waterLevel = parseInt(waterLevelHeight * waterCapacityPerCm, 10);
 
       console.log(`🚰 Tank [${tankhardwareId}] - Level: ${tankHeight}, Calculated Water Level: ${waterLevel}`);
+      if (tankHeight <= 0) {
+        if (existingTank.slave_status !== "not_working") {
+          const disconnectedTime = moment().tz('Asia/Kolkata').format('DD-MMM-YYYY - HH:mm:ss');
+          existingTank.slave_status = "not_working";
+          existingTank.slave_disconnected_time = disconnectedTime;
+          await existingTank.save();
+          console.log(`⚠️ Slave disconnected for tank [${tankhardwareId}] at ${disconnectedTime}`);
+        } else {
+          console.log(`⏩ Slave already marked as not_working for tank [${tankhardwareId}], skipping update.`);
+        }
+      }
+      
 
       if (tankHeight > 0 && waterLevel >= 0) {
         existingTank.waterlevel = waterLevel;
+        existingTank.slave_status = "working";
+        existingTank.slave_disconnected_time = null;
         await existingTank.save();
 
         for (const outputConnection of existingTank.connections.outputConnections) {
diff --git a/src/models/tanks.js b/src/models/tanks.js
index c6d700d3..5627fa8f 100644
--- a/src/models/tanks.js
+++ b/src/models/tanks.js
@@ -64,6 +64,8 @@ const tanksSchema = new mongoose.Schema({
   notificationSentHigh: { type: Boolean },
   all_motor_status: { type: Boolean },
   status:{ type: String, default: "active" },
+  slave_status:{ type: String, default: "working" },
+  slave_disconnected_time   :{ type: String, default: null },
   
   connections: {
     source: { type: String },