diff --git a/src/controllers/tanksController.js b/src/controllers/tanksController.js
index bc814f40..2ba7e615 100644
--- a/src/controllers/tanksController.js
+++ b/src/controllers/tanksController.js
@@ -656,7 +656,8 @@ exports.motorAction = async (req, reply) => {
     console.log(sump_final_water_level,"2")
     sump_water_levels = sump_water_levels.filter(tank => tank.supplier_tank !== supplier_tank);
 
-     const quantity_delivered = sump_water_level1-sump_final_water_level
+    const quantity_delivered = Math.abs(sump_water_level1 - sump_final_water_level);
+
 
      if (supplier_tank_type === "sump") {