Index: firmware/App/Controllers/BalancingChamber.c
===================================================================
diff -u -r02dbfcdab541781a4ba310eb6e7f9278c0764887 -r483ebbb75171ec93ab24d1f69f83a6248376266f
--- firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 02dbfcdab541781a4ba310eb6e7f9278c0764887)
+++ firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 483ebbb75171ec93ab24d1f69f83a6248376266f)
@@ -66,6 +66,9 @@
 #define BC_BICARB_SPEED_OFFSET_MLPM                 240.0F                                      ///< Bicarb speed formula offset (mL/min).
 #define BC_BICARB_SPEED_DISC_CONST                  230400.0F                                   ///< Bicarb speed formula discriminant constant.
 #define BC_BICARB_SPEED_DISC_VOL_COEF               96000.0F                                    ///< Bicarb speed formula volume coefficient.
+#define BC_ACID_SPEED_OFFSET_MLPM                   160.0F
+#define BC_ACID_SPEED_DISC_CONSTANT                 102400.0F
+#define BC_ACID_SPEED_DISC_VOL_COEF                 96000.0F
 
 /// Payload record structure for balancing chamber switch only request
 typedef struct
@@ -142,6 +145,7 @@
 static void closeFreshSideValvesWhenFillComplete( void );
 static void calculateBalancingChamberError( void );
 static F32 getBicarbConcentratePumpSpeedMlMin( F32 bicarbVolumeMl );
+static F32 getAcidConcentratePumpSpeedMlMin( F32 acidVolumeMl );
 static void startBalChamberConcPumpDosing( F32 acidVolume, F32 bicarbVolume );
 
 /*********************************************************************//**
@@ -210,6 +214,41 @@
 
 /*********************************************************************//**
  * @brief
+ * The getAcidConcentratePumpSpeedMlMin function computes D11 pump speed
+ * from the instantaneous acid mix volume:
+ *   speed = 160 - sqrt(102400 - 96000*v) / 2
+ * Result is clamped to [CONCENTRATE_PUMP_MIN_SPEED, CONCENTRATE_PUMP_MAX_SPEED].
+ * @details \b Inputs: acidVolumeMl
+ * @details \b Outputs: none
+ * @param acidVolumeMl Instantaneous acid mix volume (mL)
+ * @return Acid concentrate pump speed (mL/min)
+ *************************************************************************/
+static F32 getAcidConcentratePumpSpeedMlMin( F32 acidVolumeMl)
+{
+
+    F32 discriminant = BC_ACID_SPEED_DISC_CONSTANT - ( BC_ACID_SPEED_DISC_VOL_COEF * acidVolumeMl );
+    F32 result       = 0.0F;
+
+    if ( discriminant < 0.0F )
+    {
+        discriminant = 0.0F;
+    }
+
+    result = BC_ACID_SPEED_OFFSET_MLPM - ( sqrtf( discriminant ) / 2.0F );
+
+    if ( result > CONCENTRATE_PUMP_MAX_SPEED )
+    {
+        result = CONCENTRATE_PUMP_MAX_SPEED;
+    }
+    else if ( result < 0.0F )
+    {
+        result = CONCENTRATE_PUMP_MIN_SPEED;
+    }
+
+    return result;
+}
+/*********************************************************************//**
+ * @brief
  * The getBicarbConcentratePumpSpeedMlMin function computes D10 pump speed
  * from the instantaneous bicarb mix volume:
  *   speed = 240 - sqrt(230400 - 96000*v) / 2
@@ -256,7 +295,7 @@
  *************************************************************************/
 static void startBalChamberConcPumpDosing( F32 acidVolume, F32 bicarbVolume )
 {
-    F32 acidSpeed   = DOSING_ACID_CONCENTRATE_PUMP_SPEED;
+    F32 acidSpeed   = getAcidConcentratePumpSpeedMlMin( acidVolume );
     F32 bicarbSpeed = getBicarbConcentratePumpSpeedMlMin( bicarbVolume );
 
     setConcentratePumpTargetSpeed( D11_PUMP, acidSpeed, acidVolume );