Trees sucking sap back out of container?

[Dave Evenson]

I think I read somewhere on this site that if your line runs into the liquid, That the trees can actually pull sap back, just like they do out of roots. True?
I just ran a few gravity lines last year, don't remember whether my line to container was at the bottom of the container or not- I did get appropriate amount of sap, I thought. But I've been running drop lines on taps to buckets sitting on the ground for years, some with an air space, some with line on bottom of container for years. I'll make sure I have air space if true. Thanks, Dave Evenson

[TheNamelessPoet]

it is true! as the temps cause the pressure to reverse.. there goes your sap!

[spud]

The CV2 spout will prevent that from happening. When sap goes back into the tap hole it brings bacteria with it. This is what causes tap holes to dry up sooner. The CV2 spout will allow you to maximize your production on every tap hole.

Spud

[Jeff E]

In Theory...but the CV2 doesn't always work perfectly.
Better to have a practice of not having a system that allows that back flow. Such as leave vacuum on until things freeze solid, or don't have taps with tubing going into buckets. better to have taps with no tubing, dropping directly into bucket or bag...
Best practices to maximize production.
Maybe not a big issue for a hobbiest who only want to collect for a few weeks. But if it is paying bills, you want to learn the best practices Dr. Perkins and others have been researching, posting, publishing.

[Dave Evenson]

Thanks all. I'm about half on bags, so no issue, or gravity tubing, again no issue as long as I leave tubing above collection level. The others are drops to buckets, and I'm leaving air space in those now. I thought I'd read a lot, obviously not enough, over the past decade or so, but had not read this until this year. Hobbyist, so less issue, still hate to give up hard earned sap! Thanks, Dave Evenson

[Sugarmaker]

I have some pf my collection hoses going into the sap and some not. I have never noticed sap running back up the tubing in 10 years. Not saying it couldn't happen I have never seen it. My sap quantity doesn't seem to vary much from normal. I dont see and containers sucked dry. I do get them froze into a ice block and dont run sap till thawed. I guess I should have them all out of the sap. Maybe when I gather next time I will snip them short above the typical sap line?
I actually think there may be a advantage to having them submerged I believe they dont start to get bacteria as quickly if in the sap rather than the air?
Just my 2 pennies.
Regards,
Chris