I have an Aquamedic bubble counterBubble Counter by Aqua Medic - AquaCave and the instructions say to fill 1/3rd with liquid.

* my problem is that 1/3rd us just at the point where the tube of the inlet is hanging inside and I don't know if I am supposed to submerse the tube in liquid or fill it to just below the tube.

Here is a pick to see


So should I fill it just above this inlet tube OR fill the container to just below this tube.?