venting spouts

[katmike]

I have mostly buckets and run a small tubes from the tap to the buckets that rest on the ground. I have been using vented spouts since I assumed that was best to allow the sap to flow more freely. But based on what I recently read here, that would intorduce more bacteria into the taphole since there's more exposure to air. Would I be better off by NOT venting? In most cases the tube is only 1 foot long.

[happy thoughts]

That's about my own set up except without the venting. I'd say don't vent. I think the shortness of your vented tubes would make matters worse not better. My thinking here is that you'll have heavy bacterial growth in the tubes at the vent site where air is most abundant and that's a short distance to travel into the tap hole. You're going to get bacteria no matter how you set things up but it's probably not best to encourage the little buggers:)

[pierre]

i would not use them no venting and make sure the tube just enters the bucket so not to get down in the sap so it does not suck it back up into tree and contaminate the hole just my 2cents good luck this season

[Pibster]

Will the tree really draw the sap back into the hole? My tubes are probably around 1-1/2' long running into water jugs. I was worried about the jug filling up and backing up into the tree but never considered that the lines might act like a straw.

[pierre]

if the tube is deep enough into the sap it will suck it back into the tree when the sap stops running

[PerryW]

Will the tree really draw the sap back into the hole? My tubes are probably around 1-1/2' long running into water jugs. I was worried about the jug filling up and backing up into the tree but never considered that the lines might act like a straw.

If you do NOT have a sag in the pipe between the spout and the outlet in the bucket, I doubt the sap will suck back into the tree. It is more of a problem when a sag in the dropline fills with sap, and freezes.

[happy thoughts]

Will the tree really draw the sap back into the hole? My tubes are probably around 1-1/2' long running into water jugs. I was worried about the jug filling up and backing up into the tree but never considered that the lines might act like a straw.

Yes I would think so. Sap flow is all about pressure differences within the tree that can vary greatly with the pressure of the atmosphere outside the tree both positive and negative. Search for the recent thread on weather forecasts where we talked about the effect of air pressure on sap flow. One of the last posts linked to a very good article on sap flow. It might help you understand the why behind it. At freezing temps when sap flow stops, the pressure inside the tree can drop below the pressure outside it. That's when it will start sucking sap back up into itself, a simple demonstration of the direction of flow across pressure gradients.

[Pibster]

My lines are almost vertical. I did leave some of the lines long since the jugs will lower as the snow melts.

[buckeye gold]

I set up with tubes into 5 gallon buckets. I had a few vented tubes someone gave me. They did get cruddy and I think the trees gave less. I'm staying with the regular taps. I also like just a little bow in my line so a little sap stays in the line and during no run periods air isn't getting to the tap hole. I may be nuts and it's ok for someone to correct me

[Mikeh]

Here's my two cents:

1st cent: I went to a presentation where the guy talked about a tubing system he visited. When the trees stopped flowing and started sucking the sap back up, the guy couldn't chase the sap up the main line fast enough. Now that was probably a lot of trees but it means they do suck it back in. That's why Dr. Tim came up with the check valve adapter that keeps the sap from going back into the tap. I'm trying them out for the first time this year.

2nd cent: I also have drop tubes going into 5 gallon pails (under the lid). This year i did some with 5/16 tubing and some with 7/16 tubing. The main problem I deal with is a bit of sap freezing where the tubing goes under the lid of the pail. Especially on colder days (32-37 degrees) when the sap runs but it isn't warm enough to melt the sap plug. At lunch last Saturday (35 degrees) I checked them and the frozen sap plug was blocking the flow and sap was backed up to the tap. The trees where I went with bigger tubing weren't frozen (or not completely frozen) and they were running just fine. I don't really have a dip but I think the surface tension of the sap bridges across the smaller tubing at the end of the tube.

I'm still learning though...