I had already gotten mine set up and working great. But then I was still scratching my head about how exactly it worked. Lol, I appreciate the explainer.
You didn't mention how the water level increases or decreases...does tightening the adjuster nut placing more pressure on the spring DECREASE the water level?
As you turn the adjustment nut down clockwise it will put more pressure on the spring and increase the water level in the bell. To decrease the water level, turn the nut counter-clockwise. Hope this helps and that the waterer works well for your poultry!