The Bubbler is the black insert inside of the Tritan (clear) part of your Airlock.

Make sure your bubbler is inserted with the bubble-exit placed right above the LEDs. The sensor that counts the bubbles is located right below and so they must align. Check that your Bubbler is inserted and aligned correctly.

The bubbles should be breaking the water right above the LEDs. 👇🏼

If the Bubbler is not pushed all the way down the bubbles will be released too early and be too small to be counted by the sensor. Push down on the Bubbler to make sure it is seating right on the base of the Tritan.

With the Bubbler correctly inserted and seated inside of the Tritan (clear part), you can now insert both parts into the Smart-Part of your Airlock. You should hear it click once it is inserted correctly and in place.