Index: dialin/common/msg_ids.py
===================================================================
diff -u -r099d6838f82efa3d596848922793d5e56dbd541b -r9790d4c89a67940465d74dc98ee13834bee8565c
--- dialin/common/msg_ids.py	(.../msg_ids.py)	(revision 099d6838f82efa3d596848922793d5e56dbd541b)
+++ dialin/common/msg_ids.py	(.../msg_ids.py)	(revision 9790d4c89a67940465d74dc98ee13834bee8565c)
@@ -416,6 +416,7 @@
     MSG_ID_DG_SET_USAGE_INFO_RECORD = 0xA054
     MSG_ID_DG_SEND_USAGE_INFO_RECORD = 0xA055
     MSG_ID_DG_SET_OP_MODE_REQUEST = 0xA056
+    MSG_ID_DG_RESERVOIR_TARE_REQUEST = 0xA057
 
     MSG_ID_HD_DEBUG_EVENT = 0xFFF1
     MSG_ID_DG_DEBUG_EVENT = 0xFFF2
Index: dialin/dg/reservoirs.py
===================================================================
diff -u -r3a70bfb451b74106348c064c34f19934aadd9119 -r9790d4c89a67940465d74dc98ee13834bee8565c
--- dialin/dg/reservoirs.py	(.../reservoirs.py)	(revision 3a70bfb451b74106348c064c34f19934aadd9119)
+++ dialin/dg/reservoirs.py	(.../reservoirs.py)	(revision 9790d4c89a67940465d74dc98ee13834bee8565c)
@@ -112,6 +112,26 @@
 
         return True
 
+    def cmd_reservoir_tare(self, reservoir: int) -> bool:
+        """
+        Sends a command to the DG to tare a given reservoir
+        @param reservoir: (int) the ID of the reservoir to tare
+        @return: True if command sent, False if reservoir ID invalid
+        """
+
+        if reservoir not in [0, 1]:
+            return False
+
+        payload = integer_to_bytearray(reservoir)
+        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id,
+                                              message_id=MsgIds.MSG_ID_DG_RESERVOIR_TARE_REQUEST.value,
+                                              payload=payload)
+
+        self.logger.debug("Sending command to tare DG reservoir {0}".format(reservoir))
+        self.can_interface.send(message, 0)
+
+        return True
+
     @publish(["active_reservoir", "fill_to_vol_ml", "drain_to_vol_ml", "time_reservoir_cycle",
               "time_reservoir_fill_2_switch", "time_uf_decay", "temp_uf_fill", "temp_reservoir_use_actual",
               "temp_reservoir_end_fill", "temp_avg_fill", "temp_last_fill", "time_rsrvr_fill"])