Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r18ff3484c0eb42b22197d86312013196ab79584c -r9d20238b17f5c9089db526fd65c32c19927c6c0c
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 18ff3484c0eb42b22197d86312013196ab79584c)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 9d20238b17f5c9089db526fd65c32c19927c6c0c)
@@ -92,12 +92,12 @@
 static HD_PRE_TREATMENT_MODE_STATE_T currentPreTreatmentState;          ///< Current state of pre-treatment mode state machine.
 static BOOL fillReservoirOneStartRequested;                             ///< Flag indicates fill reservoir one has been requested.
 static U32 preTreatmentPublishTimerCounter;                             ///< Pre-treatment data broadcast timer counter used to schedule when to transmit data.
+
 /// Interval (in task intervals) at which to publish pre-treatment mode data to CAN bus.
 static OVERRIDE_U32_T preTreatmentModePublishInterval = { PRE_TREATMENT_DATA_PUB_INTERVAL, PRE_TREATMENT_DATA_PUB_INTERVAL, PRE_TREATMENT_DATA_PUB_INTERVAL, 0 };
 static U32 submodeCompleteTransitionTimeCounter;                        ///< Sub-mode completed transition wait time counter.
 
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T currentReservoirMgmtState;          ///< Current pre-treatment reservoir management state.
-static DG_RESERVOIR_ID_T activeReservoir = DG_RESERVOIR_2;
 static PRE_TREATMENT_RESERVOIR_VAR_T reservoirStatus[ NUM_OF_DG_RESERVOIRS ];   ///< Detailed state of each reservoir.
 
 #ifndef _RELEASE_
@@ -925,9 +925,6 @@
  *************************************************************************/
 static void execPreTreatmentReservoirMgmt( void )
 {
-    // update the active reservoir.
-    activeReservoir = getDGActiveReservoir();
-
     // treatment reservoir mgmt. state machine
     switch ( currentReservoirMgmtState )
     {
@@ -1012,6 +1009,7 @@
     PRE_TREATMENT_RESERVOIR_MGMT_STATE_T state = PRE_TREATMENT_RESERVOIR_MGMT_DRAIN_CMD_STATE;
     DG_OP_MODE_T dgOpMode = getDGOpMode();
     U32 dgSubMode = getDGSubMode();
+    DG_RESERVOIR_ID_T activeReservoir = getDGActiveReservoir();
 
     // If DG has not started yet, start DG
     if ( DG_MODE_STAN == dgOpMode )
@@ -1109,7 +1107,7 @@
             // Start tracking flush cycles, flushComplete => don't drain again.
             if ( FALSE == reservoirStatus[ inactiveReservoir ].flushComplete )
             {
-                if (0 < reservoirStatus[ inactiveReservoir ].flushCount)
+                if ( reservoirStatus[ inactiveReservoir ].flushCount > 0 )
                 {
                     reservoirStatus[ inactiveReservoir ].flushCount -= 1;
                 }
@@ -1119,7 +1117,7 @@
                 }
             }
 
-            volume = getPreTreatmentFillVolume( activeReservoir );
+            volume = getPreTreatmentFillVolume( inactiveReservoir );
             cmdStartDGFill( volume, DEFAULT_TARGET_FILL_FLOW_RATE_LPM );
             state = PRE_TREATMENT_RESERVOIR_MGMT_FILL_CMD_RESP_STATE;
         }
@@ -1178,21 +1176,34 @@
     PRE_TREATMENT_RESERVOIR_MGMT_STATE_T state = PRE_TREATMENT_RESERVOIR_MGMT_FILL_COMPLETE_STATE;
     DG_OP_MODE_T dgOpMode = getDGOpMode();
     U32 dgSubMode = getDGSubMode();
+    DG_RESERVOIR_ID_T inactiveReservoir = getDGInactiveReservoir();
+    DG_RESERVOIR_ID_T activeReservoir = getDGActiveReservoir();
 
     if ( ( DG_MODE_GENE == dgOpMode ) && ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode ) )
     {
-        state = PRE_TREATMENT_RESERVOIR_MGMT_REQUEST_RESERVOIR_SWITCH_STATE;
-
         if ( ( TRUE == reservoirStatus[ DG_RESERVOIR_1 ].flushComplete ) &&
              ( TRUE == reservoirStatus[ DG_RESERVOIR_2 ].flushComplete ) )
         {
-               reservoirStatus[ activeReservoir ].fillComplete = TRUE;
+            if( FALSE == reservoirStatus[ DG_RESERVOIR_1 ].fillComplete )
+            {
+               reservoirStatus[ DG_RESERVOIR_1 ].fillComplete = TRUE;
+               state = PRE_TREATMENT_RESERVOIR_MGMT_REQUEST_RESERVOIR_SWITCH_STATE;
+            }
+            else
+            {
+               if ( FALSE == reservoirStatus[ DG_RESERVOIR_2 ].fillComplete )
+               {
+                   reservoirStatus[ DG_RESERVOIR_2 ].fillComplete = TRUE;
+                   state = PRE_TREATMENT_RESERVOIR_MGMT_COMPLETE_STATE;
+               }
+            }
         }
         else
         {
             DG_SWITCH_RSRVRS_CMD_T rsrvrCmd;
+            state = PRE_TREATMENT_RESERVOIR_MGMT_REQUEST_RESERVOIR_SWITCH_STATE;
 
-            rsrvrCmd.reservoirID                     = activeReservoir;
+            rsrvrCmd.reservoirID                     = inactiveReservoir;
             rsrvrCmd.useLastTrimmerHeaterDC          = FALSE;
             cmdSetDGActiveReservoir( &rsrvrCmd );
         }