Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rde9afc922d50eb0328cd107d7e03540a648b1f5b -r353cb96644812b6278a5b2d98c1b7946a5c47d6e
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision de9afc922d50eb0328cd107d7e03540a648b1f5b)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 353cb96644812b6278a5b2d98c1b7946a5c47d6e)
@@ -76,6 +76,7 @@
 
 #define MAX_RO_REJECTION_RATIO_ALLOW                    0.10F                                                ///< Maximum RO rejection ratio.
 #define MAX_CPO_CONDUCTIVITY_ALLOW                      100.0F                                               ///< Maximum CPo sensor conductivity value.
+#define MIN_FILL_TARGET_TO_CHECK_RO_AND_CPO_ML          550                                                  ///< Minimum fill target to check the RO and CPo alarms in milliliters.
 
 // 2m long tubing to cap = 19.5 mL (acid line) + 7.92 mL/m * 2 m (tubing to cap) + 20.82 mL (straw) = 56.15 mL
 // Prime time in seconds = ( 56.15 mL / 48 mL/min ) x 60 second/min + 25 seconds margin time = 95 seconds.
@@ -833,19 +834,22 @@
         if ( getSoftwareConfigStatus( SW_CONFIG_DISABLE_RO_RATIO_CHECK ) != SW_CONFIG_ENABLE_VALUE )
 #endif
         {
-            F32 avgCPo = sumFillCPoConductivity / (F32)fillCPoConductivitySampleCnt;  // sample count incremented above w/o condition so no need for divide by zero checks
-            F32 avgRR  = sumFillRejRatio / (F32)fillCPoConductivitySampleCnt;
-
-            if ( avgCPo > MAX_CPO_CONDUCTIVITY_ALLOW )
+            if ( getTargetFillVolumeML() > MIN_FILL_TARGET_TO_CHECK_RO_AND_CPO_ML )
             {
-                // Fault alarm per PRS 483
-                SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_OUTLET_PRIMARY_CONDUCTIVITY_OUT_OF_RANGE, avgCPo, MAX_CPO_CONDUCTIVITY_ALLOW );
+                F32 avgCPo = sumFillCPoConductivity / (F32)fillCPoConductivitySampleCnt;  // sample count incremented above w/o condition so no need for divide by zero checks
+                F32 avgRR  = sumFillRejRatio / (F32)fillCPoConductivitySampleCnt;
+
+                if ( avgCPo > MAX_CPO_CONDUCTIVITY_ALLOW )
+                {
+                    // Fault alarm per PRS 483
+                    SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_OUTLET_PRIMARY_CONDUCTIVITY_OUT_OF_RANGE, avgCPo, MAX_CPO_CONDUCTIVITY_ALLOW );
+                }
+                if ( avgRR > MAX_RO_REJECTION_RATIO_ALLOW )
+                {
+                    // Fault alarm per PRS 483
+                    SET_ALARM_WITH_2_F32_DATA( ALARM_ID_RO_REJECTION_RATIO_OUT_OF_RANGE, avgRR, MAX_RO_REJECTION_RATIO_ALLOW );
+                }
             }
-            if ( avgRR > MAX_RO_REJECTION_RATIO_ALLOW )
-            {
-                // Fault alarm per PRS 483
-                SET_ALARM_WITH_2_F32_DATA( ALARM_ID_RO_REJECTION_RATIO_OUT_OF_RANGE, avgRR, MAX_RO_REJECTION_RATIO_ALLOW );
-            }
         }
 
         // Check FMP vs. LC