Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rf33973bc706d7144b2b0f060ccfc97e98897ab67 -r79d199f9de9c88a7866637dbc5bf33a08d74af2a
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision f33973bc706d7144b2b0f060ccfc97e98897ab67)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 79d199f9de9c88a7866637dbc5bf33a08d74af2a)
@@ -791,14 +791,17 @@
         if ( TRUE == didTimeout( concPumpPrimeStartTimeMS, CONC_PUMPS_PRIME_CHECK_COND_SNSRS_TIME_OUT_MS ) )
         {
             /* Once the time for priming the concentrate lines has elapsed, check the mixing conductivity of the sensors
-             * If the acid and bicarb conductivity values are at about 95% of the target concentrate during fill, transition to the next state
-             * If the acid and bicarb conductivity values are not at 95% but the maximum prime time has elapsed, transition to the next state
+             * If the acid and bicarb conductivity values are at about 100% of the target concentrate during fill, transition to the next state
+             * If the acid and bicarb conductivity values are not at 100% but the maximum prime time has elapsed, transition to the next state
              */
             F32 acidConduSPerCM       = getConductivityValue( CONDUCTIVITYSENSORS_CD1_SENSOR );
             F32 bicarbConduSPerCM     = getConductivityValue( CONDUCTIVITYSENSORS_CD2_SENSOR );
             F32 acidFillConduSPerCM   = chemicalsCond.fillCondValues[ chemicalsTypes.acidType ][ FILL_COND_NORMAL_OP ].acidConduSPerCM;
             F32 bicarbFillConduSPerCM = chemicalsCond.fillCondValues[ chemicalsTypes.acidType ][ FILL_COND_NORMAL_OP ].bicarbConduSPerCM;
 
+            /* we are insisting conductivity reach 100% of expected level since signal is very noisy and peak noise will reach 100% when average is about 93%.
+             * if sensor noise is reduced, this level should also be reduced accordingly.
+             */
             if ( ( acidConduSPerCM >= ( acidFillConduSPerCM * HUNDRED_PERCENT_FACTOR ) ) && ( bicarbConduSPerCM >= ( bicarbFillConduSPerCM * HUNDRED_PERCENT_FACTOR ) ) )
             {
                 result = DG_FILL_MODE_STATE_DELIVER_DIALYSATE;