Increased natural vacuum on 5/16 gravity

[limestone]

Here’s a question I have wondered about. For years I have run the lines of my 5/16 gravity system into the collection tanks. The lines are almost always submerged in the sap. Would I get better natural vacuum if I arranged the lines so they run open ended into the tank and above the sap level. The reason I ask is sometimes when I’m pumping out the tanks I notice that the lines run faster as I’m pumping.

[maple flats]

The lines aren't normally in the sap, but as you pump it's possibly creating a temporary vacuum but only until the tubing is out of the sap.

[Sugar Bear]

Sure seems like it would, because your creating head pressure on the line, the deeper the line the more the reverse effect you will get from that head pressure, which would be pushing back on any beneficial vacuum created thereby reducing vacuum.

Do you have a gauge at the top of the line. Try putting the line in the bottom of the tank. Check your gauge, then have your line drip into the top of the tank and check your gauge again. It may not be detectable on the gauge however... not sure.

I sense that doing this with a drop into the bottom of a bucket will cause problems, both in hydro dynamics and sanitation.
Sanitation for certain a problem here.

Higher then atmospheric pressure is pushed back towards any column of sap generating vacuum or the tap hole itself if no column/vacuum exists (i.e. drops to buckets )