Vent 5\16?????

[Trapper2]

I run 150-200 foot lines of 5\16, less than 1% slope no vacuum. Should I be venting this line at the first tree or leave it as a closed system? It seems that when I pulled the first top tap last spring that the sap flowed more freely and didn't (vapor lock). Thanks Trapper

[tcross]

leave it closed.

[ennismaple]

Lots of research has been done on this - keep it closed. Venting to let the sap drain might seem helpful but in the long run it causes the tapholes to heal up faster. The gases the tree produces will help push the sap out of the lines.

[bmead]

leave it closed! research shows higher yield with a closed system than an open.

[DrTimPerkins]

.... when I pulled the first top tap last spring that the sap flowed more freely...

Yes, it'll do that. All the sap will run out quickly, then stop. After it all runs out you'll get one drop in, one drop out (or one slug in, one slug of sap out). Over the season however, venting will introduce more microbes into the system and result in considerably LESS sap. There's been several research studies done on this since tubing was introduced....all produced the same results...less sap when you vent.

[Sugarmaker]

No!
Regards,
Chris