Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rcea079b61dbd17b2ddaec99b1124248147d14e72 -rc0160362dc799802ec589d5b6cf4c2bd1face77e
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision cea079b61dbd17b2ddaec99b1124248147d14e72)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision c0160362dc799802ec589d5b6cf4c2bd1face77e)
@@ -42,9 +42,6 @@
 #define TARGET_RO_PRESSURE_PSI                          130                                         ///< Target pressure for RO pump.
 #define TARGET_RO_FLOW_RATE_L                           0.8                                         ///< Target flow rate for RO pump.
 
-#define DIALYSATE_ACID_CONCENTRATE_RATIO                ( 2.35618 / FRACTION_TO_PERCENT_FACTOR )    ///< Ratio between RO water and acid concentrate.
-#define DIALYSATE_BICARB_CONCENTRATE_RATIO              ( 4.06812 / FRACTION_TO_PERCENT_FACTOR )    ///< Ratio between RO water and bicarbonate concentrate.
-
 #define DIALYSATE_FILL_TIME_OUT                         ( 5 * SEC_PER_MIN * MS_PER_SECOND )         ///< Time out period when reservoir is not filled with correct dialysate.
 
 #define ACID_BICARB_CONCENTRATE_ADDITION_MULTIPLER      1.06                                        ///< Acid and bicarbonate concentrates make up around 6% to total volume.
@@ -421,10 +418,14 @@
 static void handleDialysateMixing( void )
 {
 #ifndef DISABLE_MIXING
+    // TODO what should we do with start volume from the structure?
+    DG_ACID_CONCENTRATES_RECORD_T acid     = getAcidConcentrateCalRecord();
+    DG_BICARB_CONCENTRATES_RECORD_T bicarb = getBicarbConcentrateCalRecord();
+
     // Set concentrate pumps speed based off RO pump flow rate
     F32 const measuredROFlowRate = getMeasuredROFlowRate();
-    F32 const acidCP1PumpFlowRate = DIALYSATE_ACID_CONCENTRATE_RATIO * measuredROFlowRate * ML_PER_LITER;
-    F32 const bicarbCP2PumpFlowRate = DIALYSATE_BICARB_CONCENTRATE_RATIO * measuredROFlowRate * ML_PER_LITER;
+    F32 const acidCP1PumpFlowRate = acid.acidConcentrate[ CAL_DATA_ACID_CONCENTRATE_1 ].acidConcMixRatio * measuredROFlowRate * ML_PER_LITER;
+    F32 const bicarbCP2PumpFlowRate = bicarb.bicarbConcentrate[ CAL_DATA_BICARB_CONCENTRATE_1 ].bicarbConcMixRatio * measuredROFlowRate * ML_PER_LITER;
 
     setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP1_ACID, acidCP1PumpFlowRate );
     setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, bicarbCP2PumpFlowRate );