Choose a MQTT value to be displayed

Configuration
1

I’m trying to choose the right value to be displayed in HA but I only get errors or too much values.

Of all messages I like this one to be displayed to show my cold water consumption:
{“media”:“cold water”,“meter”:“mkradio3”,“name”:“water01”,“id”:“823xxx”,“total_m3”:4.5,“target_m3”:1.6,“timestamp”:“2020-01-19T20:22:52Z”}

but I also get messages like this with Unknown and with values that’s wrong:
{“media”:“Unknown”,“meter”:“mkradio3”,“name”:“water01”,“id”:“823xxx”,“total_m3”:0,“target_m3”:0,“timestamp”:“2020-01-19T20:23:11Z”}

And my HA config looks like this when I get them all:

  • platform: mqtt
    state_topic: “wmbusmeters/823xxx”
    name: “Cold water”
    unit_of_measurement: ‘m3’
    value_template: ‘{{ value_json[“total_m3”] }}’

How can I create a config to ignore all values except the media with cold water and nice value in total_m3?