[Phaeton]

Looking at the DIY hoop greenhouses I decided on an open tunnel. Due to winter snow any hoop based structure will have to be taken down in the fall. The local University did a study on tunnels and found a three week advantage. That is nice but keeping the rain off is my main goal. Last year's outdoor crop was devastated by rain.

33 sticks of 1/2" conduit, 13 four way connectors, 26 each 1/2" rebar 4' long, and a roll of 20' wide clear plastic sheeting.

The conduit jig is 1-1/2" blocks of wood screwed in place along an arc drawn on a wall. To get the 13' diameter 90 degree bend the blocks were set along a 4-1/2' diameter arc and bent to 140 degrees. They came out perfect.
The rebar was pounded two feet into the ground and the conduit slipped over the ends.

Almost too easy, although the wind storm that came up just as we were finishing caused a little excitement with 20 mph gusts on the 6 mil plastic.

Eleven plants, 8 Super auto Chaze from Flash Seeds and three auto Euforia from Dutch Passion. The auto Euforia has yielded over a quarter pound indoors, last year's outdoor was rained to death. Hope for better this year with the tunnel providing shelter.

[Phaeton]

This is pertinent to the hoop tunnel because I used 6 mil clear plastic sheeting for the covering. This is a common covering.

The light was measured inside and out during clear conditions and a 10:00 AM sun. The plastic absorbs more higher frequencies than lower, same as the atmosphere as the sun angle increases.

UVB 167 uw > 88 uw = 52%
Blue 8.3 mw > 5.3 mw = 61%
Green
Red 20.1 mw > 14.6 mw = 72%

PAR 1803 umol > 1214 umol = 67% Total intensity under the plastic versus open sun.

This is still quite a bit more than I can achieve inside so the transmission loss is accepted with a smile.
The photo is a Super auto Chaze in a 17 gallon container. Five inches now, great things are expected later.

[TnTLabs]

nice one.. good luck with this!
tires for drainage?

[stoned-trout]

I kept my hoop houses all year in new England...and new England gets a lot of freaking snow.....but I did heat mine with hydronic heating and mine were sturdier... ....YEEHAW...I don't have pics of my 98 footers ...farmtek./clearspan did me right...good luck bro...

[caligrownc]

So how tall is the tunnel in the center?

[kelly1376]

Awesome! Glad you were able to get those autos out in time. I'm excited to see how this works out for you.

[Phaeton]

It seems all diameters of conduit comes in 10' lengths. Bent to 90 degrees this come out to 13' diameter (6.5' ceiling), a 40' circle divided by pi. Putting the ends over rebar a foot and a half above the ground gave me an 8' peak as well as a full width cool air intake.
I would have stuck the conduit directly into the ground but the super autos are supposed to hit over 6'. A double row would have been too tight.

Ground is still icy 6" down so pallets or tires are under all the containers.

[caligrownc]

Nice, I just built some pvc hoops for some quick light deps this year but I'm looking into building something like that for a more permanent solution

[DG1959]

I also am just finishing up with a new greenhouse. 4 foot walls with livestock panel, then 3/4 pvc with "T" s, Greenhouse is 24' long X 12' wide and 10' tall. 6 ml. plastic and clear corrugated on the ends 4 foot down. I enclosed both ends but one end is able to open so I can drive my tiller in every year.... I am loving this!
Plants go in tomorrow, Chernobyl, Cinex, 9 lb hammer, mango kush.

[Phaeton]

The new climate pattern is holding. A nice first week or two in May followed by possible freezing and rain/snow.
78 F followed by low thirties and one morning with snowflakes falling but not sticking.
The tunnel is keeping the temperature above freezing and the plants are not dripping wet with 40 degree rain. Last year the cool and wet destroyed the entire outdoor crop. Mostly the nonstop rain.

So far it is wet more often than dry but the plants are doing really well. The tunnel keeps them dry and the one day it was over 80 F the open ends and sides kept the temperatures under 100.

Photos are today and it is raining still. The plants are doing fine, their present size is larger than many of last year's crop at the end of the season.
I have enough plastic to put the tunnel up two more times and most definitely without a doubt it will be used again next year. It making the difference between no crop (zero) last year and healthy plants this year.