Index: firmware/App/Controllers/ConcentratePumps.c
===================================================================
diff -u -r673b5a1cbab7728b638ee966627e6d926a7de092 -rac305d5eedc7fb0e85adef5cd4aa34e58e94e3b8
--- firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision 673b5a1cbab7728b638ee966627e6d926a7de092)
+++ firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision ac305d5eedc7fb0e85adef5cd4aa34e58e94e3b8)
@@ -39,7 +39,9 @@
 
 #define CONCENTRATE_PUMP_SPEED_INCREMENT                    2.0F                                                ///< Speed increase (mL/min) when controlling concentrate pump to target step speed.
 #define CONCENTRATE_PUMP_MIN_SPEED                          3.0F                                                ///< Minimum speed for concentrate pump in mL per min.
-#define CONCENTRATE_PUMP_ERROR_TOLERANCE                    0.02F                                               ///< Measured speed needs to be within 2% of commanded speed.
+#define CONCENTRATE_PUMP_SPD_OUT_OF_RANGE_TOL_WHEN_ON_PCT   0.02F                                               ///< Concentrate pump speed out of range tolerance when on in percentage.
+#define CONCENTRATE_PUMP_SPD_OUT_OF_RANGE_TOL_WHEN_OFF_MLPM 1.0F                                                ///< Concentrate pump speed out of range tolerance when off in mL/min.
+#define CONCENTRATE_PUMP_LOW_SPEED_THRESHOLD_MLPM           10.0F                                               ///< Concentrate pump low speed threshold in mL/min.
 #define CONCENTRATE_PUMP_ZERO_FLOW_RATE                     0xFFFF                                              ///< Pulse width value when zero flow rate or pump is off.
 
 #define CONCENTRATE_PUMP_VOLUME_PER_REV                     0.1F                                                ///< Volume output every revolution (mL).
@@ -57,7 +59,7 @@
 
 #define CONCENTRATE_PUMP_DATA_PUBLISH_INTERVAL              ( 1000 / TASK_GENERAL_INTERVAL )                    ///< Interval (ms/task time) at which the concentrate pump is monitored.
 #define CONCENTRATE_PUMP_CONTROL_INTERVAL                   ( 1 * MS_PER_SECOND / TASK_GENERAL_INTERVAL )       ///< Interval (ms/task time) at which the concentrate pump is controlled.
-#define CONCENTRATE_PUMP_SPEED_CONTROL_PERSISTENCE_PERIOD   ( 5 * MS_PER_SECOND )                               ///< Persistence period for concentrate pump speed control error.
+#define CONCENTRATE_PUMP_SPEED_OUT_OF_RANGE_TIMEOUT_MS      ( 10 * MS_PER_SECOND )                              ///< Concentrate pumps speed out of range timeout in milliseconds.
 
 #define NUMBER_OF_ACID_AND_BICARB_NV_DATA_TO_CHECK          1                                                   ///< Number of acid and bicarb non-volatile data to check.
 
@@ -171,8 +173,8 @@
         stopConcentratePump( pumpId );
     }
 
-    initPersistentAlarm( ALARM_ID_DG_CP1_SPEED_CONTROL_ERROR, CONCENTRATE_PUMP_SPEED_CONTROL_PERSISTENCE_PERIOD, CONCENTRATE_PUMP_SPEED_CONTROL_PERSISTENCE_PERIOD );
-    initPersistentAlarm( ALARM_ID_DG_CP2_SPEED_CONTROL_ERROR, CONCENTRATE_PUMP_SPEED_CONTROL_PERSISTENCE_PERIOD, CONCENTRATE_PUMP_SPEED_CONTROL_PERSISTENCE_PERIOD );
+    initPersistentAlarm( ALARM_ID_DG_CP1_SPEED_CONTROL_ERROR, CONCENTRATE_PUMP_SPEED_OUT_OF_RANGE_TIMEOUT_MS, CONCENTRATE_PUMP_SPEED_OUT_OF_RANGE_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_DG_CP2_SPEED_CONTROL_ERROR, CONCENTRATE_PUMP_SPEED_OUT_OF_RANGE_TIMEOUT_MS, CONCENTRATE_PUMP_SPEED_OUT_OF_RANGE_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_DG_CONC_PUMP_HALL_SENSOR_OUT_OF_RANGE, CONCENTRATE_PUMP_HALL_SENSORS_OUT_OF_RANGE_TIME_MS, CONCENTRATE_PUMP_HALL_SENSORS_OUT_OF_RANGE_TIME_MS );
     initPersistentAlarm( ALARM_ID_DG_ACID_CONCENTRATE_PUMP_PARK_FAULT, CONENTREATE_PUMP_PARK_FAULT_TIMEOUT_MS, CONENTREATE_PUMP_PARK_FAULT_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_DG_BICARB_CONCENTRATE_PUMP_PARK_FAULT, CONENTREATE_PUMP_PARK_FAULT_TIMEOUT_MS, CONENTREATE_PUMP_PARK_FAULT_TIMEOUT_MS );
@@ -856,17 +858,19 @@
     F32 cpTargetSpeed = concentratePumps[ pumpId ].currentPumpSpeed;
     F32 cpError       = fabs( getMeasuredPumpSpeed( pumpId ) - cpTargetSpeed );
     BOOL isCpSpeedOut = FALSE;
+    F32 tolerance     = CONCENTRATE_PUMP_SPD_OUT_OF_RANGE_TOL_WHEN_OFF_MLPM;
 
-    if ( cpTargetSpeed > NEARLY_ZERO )
+    if ( ( cpTargetSpeed > NEARLY_ZERO ) && ( cpTargetSpeed > CONCENTRATE_PUMP_LOW_SPEED_THRESHOLD_MLPM ) )
     {
-        // Check if the pump is not in the off state and if it is not, divide the error
-        // to target speed. If the pump is off the target speed is 0
-        cpError = cpError / cpTargetSpeed;
+        // Check if the pump is not in the off state and if it is not and greater than the minimum threshold, divide the error
+        // to target speed. If the pump is off the target speed is 0 so the speed check is done differently
+        cpError   = cpError / cpTargetSpeed;
+        tolerance = CONCENTRATE_PUMP_SPD_OUT_OF_RANGE_TOL_WHEN_ON_PCT;
     }
 
-    isCpSpeedOut = ( cpError > CONCENTRATE_PUMP_ERROR_TOLERANCE ? TRUE : FALSE );
+    isCpSpeedOut = ( cpError > tolerance ? TRUE : FALSE );
 
-    checkPersistentAlarm( alarm, isCpSpeedOut, cpError, CONCENTRATE_PUMP_ERROR_TOLERANCE );
+    checkPersistentAlarm( alarm, isCpSpeedOut, cpError, tolerance );
 }