I have created a reservoir that is intended to automatically self-fill at exactly 1/4" depth. The idea is that the reservoir is hooked up to the airtight jug and dispenses the liquid until the opening of the tubing is fully submerged in the liquid. At that point air can no longer travel up the tubing to push more liquid out and the depth of the liquid remains constant, until some liquid is removed and the reservoir refills back to the depth. However when I tested this the theory did not work and water continued to come out. When testing the reservoir was below the jug. I question whether my logic is correct? Do I have an incorrect understanding of the physics, or could the problem stem somewhere else? Maybe some air was leaking into the jug causing more liquid to pour? Could the solution be maybe dependent on the height difference between the reservoir and jug?
On another note, as you can see in the photo the part I created is actually a "2 story" reservoir. The aim is to hook a splitter up to the jug and fill the two reservoirs from the same jug. I'm thinking this may cause some more complications.
If anyone has any advice on how to make this work it would be of great help. I am also open to other suggestions. I was thinking about potentially working in a float valve into this design.