Is 34 taps on one 3/16 line too many?

[Mike Hofer]

This is correct. You'll do fine with 34 taps, but the lines are overloaded at this point so will not perform optimally. You'll do better in terms of yield by splitting it into two lines, and if a squirrel chews into one line and stops the vacuum, the other will still be good.

Can you provide the data for your statement that "...but the lines are overloaded at this point..." ?

At what point do you overload 3/16" tubing in terms of volume per unit time (gal/hour or similar)? What does "overloading" mean in practical terms, i.e. maximum recommended Taps before sap volume starts decreasing. A plot of this as you add additional taps above the recommended maximum would be helpful. I'm not sure if a well-constructed study exists for this.

The reason I ask is that I've had great results over 5 seasons on 3/16" tubing from 25-30 taps per line, lines are ~800 feet long measuring 26" of vacuum at the end tap. The first 300' of tubing from the collection tank has 75' of drop. This past season, I added about 5 taps per line and noticed significantly less sap per run and over the course of the season. Next season I think I will conduct my own study.

Thanks for any help you can provide.