Newbie Tubing Questions

[mhoven157]

Hi Everyone,

I have really enjoyed reading through many posts about tubing installation. This year I am planning on making the jump from drop-lines in buckets, to running some lines through my sugarbush. Part of my property is down the side of a drumlin with quite a bit of slope and the other portion is on flatter land. I'm not able to set up a vacuum pump so I'll be on gravity this year. Down the line I'd like to put up some main lines, but I plan on growing a little more each year to get to that point.

I have read several posts on different tubing thoughts and I have some questions that I am looking for some more clarification on:

- Several threads have mentioned using 5/16 drops with 3/16 lines, the 5/16 drops are supposed to prevent sap from being taken back into the tree. And from what I've gathered if 3/16 drops were used with 3/16 lines on gravity the sap could be taken back in leading to a smaller sap yield. Are there any benefits to using 5/16 drops on 3/16 lines that I am missing? How long should the drops be? Would using a check valve in tandem with 3/16 drops on 3/16 line prevent the sap from being pulled back into the tree?

- If using 3/16 line, is there an optimal drop from the last tree to the collection tank that would maximize sap flow?

- Am I better off just using 5/16 lines and drops leading to collection tanks for the flatter parts of the land?

Thanks so much for your input!

[maple flats]

I prefer the 5/16 drops even though many of my drops use check valve (CV) taps. The CV taps work well early in the season but some fail later as the little check ball gets sticky from micro-organisms as temperatures trend warmer. The % of such failures is still somewhat low but it still happens on at least a few. A common % in my experience might be 5-15%. To my thinking just that makes it better to use 5/16 for the drops. For the other question- drop length, for me that has changed from my early days to now. My early drops were about 24" long, then as I realized that was too short to reach around many of the trees from the tee, I gradually added length. I then tried 28" then 32" and now 36". I think 36" works best, but 32" was close. The added length is not because the trees were growing, but just that with the longer lengths I could reachthe back side of the tree in one direction or the other and reach higher as needed, and in some cases reach lower (yes, some drops tap below the lateral (a lateral is the line from tree to tree, the drop is the line from lateral to tap). I do not make the drops up at the tree except in a case where I am making a repair, but I sit at my kitchen table and make them up, thus they are all the same length.
The CV taps or CV adapters do not prevent sap from being pulled back into the tree, but they improve that a lot. However to that end, I tried what is called Zap Bac taps last year on 200. This year I will add 400 more. They have no check ball, they instead have silver (a natural anti-bacterial) blended into the plastic (nylon). While CV 's should be new every year, testing has shown the Zap Bac taps can be used for 3 seasons, this saves labor and spreads the higher tap cost over 3 seasons, which then makes them about the cost of the yearly change disposable taps.
I guess there is no optimal drop from last tree to the tank, because the vacuum at each tap is based on the elevation drop from that tree to the tank. While if you have a 35 or 40' drop or more from a tree to the tank you will get the maximum possible vacuum at that tap, but the tree that is only lets say is 15' above the tank in elevation will have less vacuum. As the lateral goes down hill the vacuum at each tap is just based on the fall from that tree to the tank. That being said, as long as you don't put too many taps on a lateral you will get more sap than if you used 5/16 laterals and at a significant cost savings. On a 5/16 lateral you should try for under 100' length laterals and 5 to max 10 taps on a line, and remember it needs constant slope to the tank. On 3/16 as long as you have the slope, there is no max length that I have ever heard, but I have heard max # of taps ranging from 20-25-30-35-37 and a few higher. I suggest you try 25-30. That being said, I have one that is about 1200-1300' long and has 42 taps, but plans are to split that into 2 laterals this season. I'm told line friction likely slowed the productivity on the best sap flow days.