Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rb1dc3df084a8517ca1575bdbf741fecd96d56a12 -ra3e3feea8cfb6a1e0137bf09031f0484a3c73332
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision b1dc3df084a8517ca1575bdbf741fecd96d56a12)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision a3e3feea8cfb6a1e0137bf09031f0484a3c73332)
@@ -54,15 +54,15 @@
 
 #define CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS        ( 5 * MS_PER_SECOND )                       ///< Persistence period for conductivity error.
 
-/// Multiplier to conver flow (mL/min) into volume (mL) for period of general task interval.
+/// Multiplier to convert flow (L/min) into volume (mL) for period of general task interval.
 static const F32 RO_FLOW_INTEGRATOR = ( ( ML_PER_LITER * TASK_GENERAL_INTERVAL ) / ( SEC_PER_MIN * MS_PER_SECOND ) );
 
 // ********** private data **********
 
 static DG_FILL_MODE_STATE_T fillState;                  ///< Currently active fill state.
 static U32 dialysateFillStartTime;                      ///< Current time when starting to fill dialysate.
 static F32 reservoirBaseWeight;                         ///< Fill reservoir base weight.
-static F32 totalROFlowRate;                             ///< Total RO flow rate over period of time.
+static F32 totalROFlowRate_LPM;                         ///< Total RO flow rate over period of time.
 static U32 concentrateTestStartTime;                    ///< Starting time for concentrate test.
 
 // ********** private function prototypes **********
@@ -89,7 +89,7 @@
     fillState = DG_FILL_MODE_STATE_START;
     dialysateFillStartTime = 0;
     reservoirBaseWeight = 0.0;
-    totalROFlowRate = 0.0;
+    totalROFlowRate_LPM = 0.0;
     concentrateTestStartTime = 0;
 
     initPersistentAlarm( ALARM_ID_ACID_CONDUCTIVITY_OUT_OF_RANGE, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS );
@@ -356,7 +356,7 @@
 {
     DG_FILL_MODE_STATE_T result = DG_FILL_MODE_STATE_DELIVER_DIALYSATE;
     DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
-    totalROFlowRate += getMeasuredROFlowRate();
+    totalROFlowRate_LPM += getMeasuredROFlowRate();
 
     handleDialysateMixing();
 
@@ -372,13 +372,13 @@
     // if we've reached our target fill to volume (by weight), we're done filling - go back to re-circ mode
     if ( hasTargetFillVolumeBeenReached( inactiveReservoir ) )
     {
-        F32 const filledWeight = getReservoirWeight( inactiveReservoir ) - reservoirBaseWeight;
-        F32 const integratedVolume = totalROFlowRate * RO_FLOW_INTEGRATOR * ACID_BICARB_CONCENTRATE_ADDITION_MULTIPLER;
-        F32 const integratedVolumeToLoadCellReadingPercent = 1 - ( filledWeight / integratedVolume );
+        F32 const filledVolume_mL = getReservoirWeight( inactiveReservoir ) - reservoirBaseWeight;
+        F32 const integratedVolume_mL = totalROFlowRate_LPM * RO_FLOW_INTEGRATOR * ACID_BICARB_CONCENTRATE_ADDITION_MULTIPLER;
+        F32 const integratedVolumeToLoadCellReadingPercent = fabs( 1 - ( filledVolume_mL / integratedVolume_mL ) );
 
         if ( integratedVolumeToLoadCellReadingPercent > FLOW_INTEGRATED_VOLUME_CHECK_TOLERANCE )
         {
-            SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_FLOW_METER_CHECK_FAILURE, filledWeight, integratedVolume );
+            SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_FLOW_METER_CHECK_FAILURE, filledVolume_mL, integratedVolume_mL );
         }
 
         requestNewOperationMode( DG_MODE_CIRC );