UVb an experiment

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Originally Posted by oldmac

BTW for everyone; while I was gone I oversaw a side by side by side experiment that had UVb from start of veg to flower to finish, Uvb for just flower period and no UVB at all. We used 5 different strains and the results are interesting. I will try to post it all in the comming days.

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More than interested on hearing about it, bro :rasta:

You are right, there is no LED growing lamp using UVB LEDs, which are very expensive (one can cost more than all the rest of the lamp). Those using "UV" LEDs actually are using near UVA, and mostly, violet (no ultraviolet) LED.

UV tecnically starts below 380nm. Although LEDs emitting in 390-410nm, which are the vast majority used on LED growing lamps, are barely visible, they are not UV, and that band effect is accounted on all botany literature as deep blue, not as UV. I do no expect large differences in biological effects than 450nm blue effect for these LEDs.

There is actually avalaible true UVA LEDs (peak emission 360-385nm), but i think little manufacturers (if any) is using them. They are mostly avalaible on low power LEDs. UV LEDs needs especial optics in the encapsulate of the chip because most materials do yellow when exposed to UV. In general UV are much short lived than blue LEDs and output degradation is faster.

Anyway, efficiency compared with royal blue LEDs is greatly reduced.

Bump

Sorry that I've taken so long to post, last few weeks I've had computer issues. While I was recuperating from an operation during the summer, I hooked up with a fellow that grows out mmj plant starts I provide to a nearby town's cancer group. He has a engineering back ground and we have had many talks about light, it's various spectrums and the effect on plants. He offered to do the work for a side by side UVb experiment, if I would guide him with the set up and provide the plant material. I've wanted to do the experiment that Rusty T talked about (see beginning of this thread), basically using UVb thru out vegative growth and then flowering.

The set up:

Built a box from 1/4" plywood, aprox 48"x30", divided into 3 sections of abt 16"x30". Each chamber would accomadate 1 greenhouse tray (abt 15"x24") that are designed to hold 15 pots that are 4 1/2" square and abt 6" high. These pots and trays are used commercially for flower and vegtable "starts" and make life easy by allowing a worker to move 15 plants at a time. BTW the trays are slotted to allow bottom feeding (ie ebb & flow).

All chambers used a 150w HPS that was mounted in a 4" pyrex (boroscilicate) glass tube that were air cooled. (poor man's cool tube using Bake a Round)
Chamber 1; was for the UVb veg & flower, so we used a 'Zilla desert 50 UVb CFL that is 20 watts. This was mounted in a small 6" diameter reflector next to the cool tube. Even tho this is a UVb bulb, it does put out a considerable amount of full spectrum light, and represents abt 15% additional light (by wattage) to the HPS bulb. So I felt I needed to add that additional light to the other chambers.
Chamber 2; was for controll, no UVb at all. So I added a 6500K 23 watt CFL, INSIDE the cool tube with the HPS. I did this to negate anything the CFL might put out to effect results. (boroscilicate glass does not pass UV light)
Chamber 3; was for no UVb during veg/ but UVb during flower. So for the veg time again a 23w CFL was added inside the cool tube, then when it came to flower it was removed and another 'Zilla 50 UVb was mounted outside the tube.

I used 5 differant strains in each chamber, 3 of each. The strains were: White Rhino, Shiva Skunk, Pure Power Plant, Cheese and "Apricot". This last one is a nick name I gave this strain because I recieved it as a cutting from a fellow in the midwest who was big on the use of apricot seeds for cancer treatment. It is a very interesting strain from the stand point of trichome production...it does not make any outside of the buds themselves, but seems to have a great deal of cannabinoids. It will increase appetite, curtail nausea from treatments and eases pain but does not have a real kick-ass high no matter how much you vape or smoke. Plus I have tried almost everything to see if I could get it more frosty but have had no success.

Grow medium was Pro-Mix BX, nutrients where Dutch Masters Gold using growth during veg stage and once into 12/12 used bloom. All chambers had the same tender loving care, and the enviroments where identical. Lights on temps where 78-80F and lights off abt 70-72F. No additional CO2 was used, just ambient levels, aprox 380 ppm. No other additional light sources were used (I usually use a far red source, but not this time).

This is getting long, so....next post will have our observations and findings.
Any questions abt the set up or experiment are welcomed and kibbitzing is encourged. :)

Its an excelent experimental design, difficult to imagine a better one out a lab!

Looking forward for your observations and results. Probably is in this area where there is going to be more subjetivity implied, as its difficult to measure amount of resin alone (except with estandarized extraction) and effect on cannabinoid profile usually only can be infered by effects on each user (again subjetive). But other effects on the grow can be seen very objetively, and for me, subjetive observations of an experienced grower and user are always a great source of reliable info (at the end, all MJ forums are founded on it).

But no doubt that you designed the experiment to be a fair competition of the 3 chambers, while being able to reasonably think that differences on end results are mostly due UVB used.

Superior!:thumbsup:

Perched on the edge, in restless anticipation.
We wait.

Mahalo nui!
Weeze

"You must spread..."

Cyanide as an alternative cancer treatment? :wtf:
I guess if it can kill you, it can kill the cancer cells too. I'm just a little wary of the unsupervised poisoning of my wife, who has been going through bi-weekly chemotherapy for about 8 years now. (t-cell lymphoma)
Apricot seeds and cyanide

Am looking forward to the experiment, and more importantly the results.
I've given the actinic bulbs a test run a few times, but never saw an identifiable result. I believe they were 380-410nm, 32w each. (two bulb fixture - 64w total)

Keep in mind that the UV doesn't reflect very well. Loses strength on the rebound. 50 is pretty strong though...how far are you keeping them from the tops, and how long are they on per day?

And for other's out there...UV light can have adverse effects on your eyes and skin. Use proper care to protect yourself and others.

Also...do the :thumbsup: icons appear in the rep comments, or does it just read as 'thumbsup'? (been wondering for a while now, lol)

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Originally Posted by Rusty Trichome

Also...do the :thumbsup: icons appear in the rep comments, or does it just read as 'thumbsup'? (been wondering for a while now, lol)

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the icons show up in the rep Rusty.

-shake

It showed up.
So did R.T.s

How d'ya do dat?

The rep box won't let me paste anything directly into it.:wtf:


Aloha,
Underprivileged 'zard

Quote:

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Originally Posted by Weezard

It showed up.
So did R.T.s

How d'ya do dat?

The rep box won't let me paste anything directly into it.:wtf:


Aloha,
Underprivileged 'zard

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okay weeze, what i did was open another tab (i use firefox) and hit reply to a random post. then find the icon you want and hover over it. it will give you the icon name. e.g., the one i sent in the rep is called stoned. when you hover over it it shows up as :"stoned":. so that's exaclty what i wrote in the rep box, minus the quotes. ( i normally would have put the quotes on the outside, but it still showed the smiley, there is no space between the : and the words. :stone*: ) (<---had to put a space here because with a : ) without the space you get a :).) wtf. sorry to get confusing!

long story short, you just need to know the name, which is probably always enclosed in :: (i guess it's BB code for an icon or whatnot) and type it in!

glad to help.


-shake