OneHitDone
Well-Known Member
Deep Red hits right around a photosynthetic peak, not a Flower Initiating NM
The far red thread
- Thread starter Rahz
- Start date
KonopCh
Well-Known Member
I already have 3000K 80 CRI, that's why. And because I want to cut off some time.
Randomblame
Well-Known Member
EOD treatment can do this within a certain range(up to a week). I see no reason why it should not work with automatics. If you add a few diodes around the COB's stay below 5% of the total output.
SAS means you'll lose up to 50% of the final yield because of less nodes, spindly stalks and fluffy buds.
SAS means you'll lose up to 50% of the final yield because of less nodes, spindly stalks and fluffy buds.
Randomblame
Well-Known Member
Yea, these 660nm pucks are more like a wake up light, 730nm is for "good night".
But white light has already enough 660nm wavelength to switch phytocromes back to it's active state.
KonopCh
Well-Known Member
If someone need to read about SAS/SAR ---> https://pdfs.semanticscholar.org/c5a1/20dff653f8dfef6aa3a0b9db310784e37c7c.pdf
All I can say for now, 15 minutes was too much and I already saw around 5cm stretch in one day! But they're in "stretch mode", 40 days old, so this must keep in mind. Anyway I will lower light to 10 minutes only.
All I can say for now, 15 minutes was too much and I already saw around 5cm stretch in one day! But they're in "stretch mode", 40 days old, so this must keep in mind. Anyway I will lower light to 10 minutes only.
Aolelon
Well-Known Member
The math was provided for you to get the optimal time required to run them I thought.
Randomblame
Well-Known Member
You always get a little more stretch with EOD treatment and the optimal amount is slightly different from strain to strain..
I'm using 2000-3000μmol/s most of the time and end up with +2-4" at the end. With most indicas you can use a bit more far-red because they are anyway not that stretchy.
I'm using 2000-3000μmol/s most of the time and end up with +2-4" at the end. With most indicas you can use a bit more far-red because they are anyway not that stretchy.
nachooo
Well-Known Member
Yes..some more stretch seems hard to avoid with EOD...Has anybody here used UVA leds with far reds at the end of the day? If yes...did the uvas stop the stretch? Did they affect the effect of dar red ones?
Randomblame
Well-Known Member
I'm using a UVA/UVB bulb over the day (~10% of the total output) and the plants stay a bit shorter because of the blueish 7500°k/CRI90 spectrum. But it is switched off with the mainlight. I'm pretty sure when I would let it run 3-5 minutes more and switch it off together with the far red trigger it would make no difference.
If UVA diodes I would use it the whole day to increase resin production and active ingredients. Not that effective like UVB but better than none. Some growers even claim you only need to use extra blue light for the last week and it would increase thc content. No idea what's wrong with this rumor ... I can only confirm UVA or UVA/B worx and the plants anyway stay a bit shorter when used for the whole day!
If UVA diodes I would use it the whole day to increase resin production and active ingredients. Not that effective like UVB but better than none. Some growers even claim you only need to use extra blue light for the last week and it would increase thc content. No idea what's wrong with this rumor ... I can only confirm UVA or UVA/B worx and the plants anyway stay a bit shorter when used for the whole day!
BuddyColas
Well-Known Member
A little aside, I'm using a GM5 puck in a 2x4 tent. I found 5 min. EOD was to much. Lots of stretch. I cut it down to 1 min. And got a faster finish and minimal added stretch. Doesn't take much to tell the girls good night!
nachooo
Well-Known Member
I am using 10 minutes of EOD..and this summer with the added heat I got more stretch tan usual...Think I gonna follow your route and reduce EOD...Will be nice to know exactly the mínimum time/watts per square meter of Far red needed…
Randomblame
Well-Known Member
It takes usually 2000-4000μMol for EOD treatment, the minimum is different from strain to strain and it is more a greenhouse rule from commercial gardeners. I'm using 2000-2500 most of the time and get only a little more stretch if any. I've not tried it with even less far-red 'cause it was simply not neccessary but would be interesting to find out what the absolut minimum is for cannabis.
nachooo
Well-Known Member
Thanks for the info….I am using cheap far reds..I bought them some years ago to an eBay chinese seller… who knows how many μMol per watt they are providing….probably they are epistar or similar brand...
Randomblame
Well-Known Member
No clue, there are no datasheets about these diodes but I would calculate with no more than 20-25% effiency to get an idea for a start point. 5+5mins with Cree/Osram diodes would probably be like 10+10mins with cheap old Epi diodes.
But you need anyway to figure out how much works best in your enviroment. Plants react pretty fast to too much far-red as they change leaf colors into a brighter green and leafes gets muuuch bigger and they stretch unnaturally but only the main stem. If you see such changes it's already too much!
There is also some point where you see absolute no difference if its too less. And like mentioned by @wietefras the profits are proportional to the amount of far red. That means the plants mature faster with 4000 than with only 1000μMol's. But you only need to stay below the saturation point to avoid SAS.
For me it works best when I see only minimal changes on the plants. The stems should remain firm and woody like before and not be softened by too fast growth, the leaves may only be slightly larger but with no color changes and when stretching the branches must also grow like the stem. All of these are pointers to recognize SAS that one can easy keep an eye on.
In the best case plants end up a few inches higher but most of the time its less than 4", maybe up to 8" with some extreme stretchy sativas like BlueDream or Flo.
nachooo
Well-Known Member
I have seen this bright green leaves…. and too much stretch..but I have also see them finish 2 weeks earlier….And with early indicas if I use far red and 11/13 or 10/14..they mature so quick that buds are little than usual..but quality is the same...
Purpsmagurps
Well-Known Member
thanks for clearing that up
Randomblame
Well-Known Member
Yea, that's already a light form of SAS. If you find the sweetspot, they may only be a week faster, but you will not have so much loss. The goal is to increase the annual yield and an additional run can only do that if the losses per run are not too high.
I use far red to achieve exactly the opposite!
For me, shortening makes no sense, since I can only do 2 or 3 runs per year anyway. Therefore I change from BW2 to 14/10(ind) or 13,5/10,5(sat) for ~5 weeks and then slowly go back hour by the hour. From the 8th week they get 11/13 and I finish the run with 10/14.
Most of the time it ends with an extra week(7-10 days) and a yield increase of ~5-10%.
nachooo
Well-Known Member
To avoid potential production losses I have increased the light intensity not only to mantain same DLI than in my usual 12/12, as I flower less days overall, I have increased the DLI even more...to compensate not only the 2 hours less every day (10/14)… also the difference of days in flower…
I am running about 6 crops a year… This allows me much more genetic experimenting than only 3 crops a year..the old way with HPS when I was unable to flower in summer and did not know how to manipulate photoperiod and the use of far red..
The nice thing about far red is that you can choose the way way you can use it ..althought is a doble edge sword...
Some years ago I follow your route with indicas at 14/10...and the production skyrocket…. but some bananas happens at the end...nice old way to feminize like rodelization