Vent tube length

Hi, I’ve just moved over to GHL and having been setting up the KHD, still learning and calibrating many times to get consistency and close to my own dkh tests.

My sample tube length is 81cm, but I have my waste and vent tubing going to a sink (maybe 3m) so I don’t have to empty containers. I know the instructions says that the vent tube must be above the liquid level of the waste container, but does it matter if my vent tube is very long and water remains In the tubing after the measurements are completed?

The 3m distance will not a be problem as long as the tube is headed downwards.