Threshold Sensor Question

If you just want a binary sensor to be on when within a range use a template binary sensor.

configuration.yaml

template:
  - binary_sensor:
      - name: "pH in Range"
        device_class: problem
        state: "{{ 7.2 < states('sensor.your_ph_sensor_here')|float(0) < 7.6 }}"

FYI: one of the reasons you may not have received a reply to your linked topic is that you posted pictures of text rather than the actual text correctly formatted for the forum. Posting the text makes it a lot easier for people to help you using copy/paste/edit.