Index: leahi_dialin/dd/modules/concentrate_pump.py
===================================================================
diff -u -r27204a288bc534f1f2d5a7eb9ca5fb31d7664b92 -r6c52c3221833245403fefa88deaeb41c52492936
--- leahi_dialin/dd/modules/concentrate_pump.py	(.../concentrate_pump.py)	(revision 27204a288bc534f1f2d5a7eb9ca5fb31d7664b92)
+++ leahi_dialin/dd/modules/concentrate_pump.py	(.../concentrate_pump.py)	(revision 6c52c3221833245403fefa88deaeb41c52492936)
@@ -363,21 +363,23 @@
             return False
 
 
-    def cmd_concentrate_set_start_stop(self, pump_id: int, command: int, speed: float ) -> int:
+    def cmd_concentrate_set_start_stop(self, pump_id: int, command: int, speed: float, volume: float ) -> int:
         """
         Constructs and sends the concentrate pump start stop command
 
         @param pump_id: unsigned int - concentrate pump ID
         @param command:  int - value to command the concentrate pump
         @param speed:  float - ml/min to set the speed to
+        @param volume: float - the volume to set to
         @return: 1 if successful, zero otherwise
 
         """
 
         pmp = integer_to_bytearray(pump_id)
         cmd = integer_to_bytearray(command)
         spd = float_to_bytearray(speed)
-        payload = pmp + cmd + spd
+        vlm = float_to_bytearray(volume)
+        payload = pmp + cmd + spd + vlm
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dd_ch_id,
                                               message_id=MsgIds.MSG_ID_DD_CONCENTRATE_PUMPS_START_STOP_OVERRIDE_REQUEST.value,