7/16 or 5/16 spouts

[wkies]

I'm torn. Do I use 7/16 or 5/16 spouts for a 175 tap gravity system? I know there are positives and negatives for both including sap production and tree health. What are others using?

I have used both and often change out the drops and spouts each season but after reading a variety of different posts recently I'm not sure which way to go for 2013.

[Thompson's Tree Farm]

In general, most research shows 90% of the production and about half the scarring for a 5/16 vs. a 7/16 spout. That's a no brainer!

[spencer11]

Use 5/16" seasonals so you will have new plastic in the tap hole each year, they are 5/16" and with the smaller taps it doesn't scar the tree as bad and you only get a little less sap per tap

[wkies]

What brought this up was an early post. Dr. Tim suggested that 5/16 can reduce the annual yield by 5% to 20%. 20% is pretty significant.

[spencer11]

On gravity you will get an average of 10-15 galling of sap per tap per season, so 20% of that is an average of 2.5 gallonsmofmsap per tap per season loss, it does add up, BUT with 7/16" taps you don't get new plastic in the tap hole each year like you can with smaller one, and that alone should make up for the lost sap

[wkies]

I do change my drop and spouts each season so I am getting new plastic in each season.

[spencer11]

Seems like you spend a lot of extra money doing that, I wouldn't change your drops every year, maybe every 4 or 5 years. And the only 7/16" taps for tubing I've seen are like $ .40 or $ .50 each, you can get seasonal spouts for as little as $ .16, I think it's worth the switch, it will save you a lot of money, do less harm to the tree, and if you don't change your drops every year, a lot less work

[TapME]

I have buckets and mainline and have changed all over to 5/16, except for a couple show me buckets. To get to the topic I have not seen a large reduction in sap from changing to the 5/16. This is my experience. Also the healing in the tree has been in one season vs 2 for the 7/16.