Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rd00c946bf5f9044e71d8d205d7425c2485d82f8e -r843259598eb3cda17ddd370672218a58ef3a6392
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision d00c946bf5f9044e71d8d205d7425c2485d82f8e)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 843259598eb3cda17ddd370672218a58ef3a6392)
@@ -68,6 +68,8 @@
 #define FLOW_INTEGRATED_VOLUME_CHECK_TOLERANCE          0.1F                                                 ///< Flow integrated volume has 10% tolerance compare to load cell reading.
 
 #define FIVE_PERCENT_FACTOR                             0.05F                                                ///< 5.0 / 100.0  used to calculate conductivity within range of -/+ 5%.
+#define BICARB_CHECK_TOL_PCT                            0.2F                                                 ///< Bicarb check tolerance in percent.
+#define ACID_CHECK_TOL_PCT                              0.1F                                                 ///< Acid check tolerance in percent.
 #define RO_PUMP_LOOKUP_TABLE_SIZE                       4                                                    ///< Size of array used as RO pump speed lookup table.
 #define CONCENTRATE_PUMP_PRIME_EXTRA_SPEED_ML_MIN       5.0F                                                 ///< Concentrate pump additional speed during priming in mL/min.
 #define CONCENTRATE_TEST_TIME_OUT_MS                    ( 30 * MS_PER_SECOND )                               ///< Concentrate test time out period in ms.
@@ -701,7 +703,7 @@
 
         SEND_EVENT_WITH_2_F32_DATA( DG_EVENT_BICARB_CHECK_RESULT, averageBicarbConductivity, bicarbCondUSPerCM )
 
-        if ( TRUE == isValueWithinPercentRange( averageBicarbConductivity, bicarbCondUSPerCM, FIVE_PERCENT_FACTOR ) )
+        if ( TRUE == isValueWithinPercentRange( averageBicarbConductivity, bicarbCondUSPerCM, BICARB_CHECK_TOL_PCT ) )
         {
             isConductivityInRange = TRUE;
         }
@@ -760,7 +762,7 @@
         SEND_EVENT_WITH_2_F32_DATA( DG_EVENT_ACID_CHECK_RESULT, averageAcidConductivity, acidCondUSPerCM )
         SEND_EVENT_WITH_2_F32_DATA( DG_EVENT_COND1_VS_COND2_DIFF_RESULT, pctDiffInConductivity, 0.0F )
 
-        if ( ( TRUE == isValueWithinPercentRange( averageAcidConductivity, acidCondUSPerCM, FIVE_PERCENT_FACTOR ) ) ||
+        if ( ( TRUE == isValueWithinPercentRange( averageAcidConductivity, acidCondUSPerCM, ACID_CHECK_TOL_PCT ) ) ||
              ( TRUE == getTestConfigStatus( TEST_CONFIG_MIX_WITH_WATER ) ) )
         {
             hasAcidTestPassed = TRUE;