660 or 720 nm to wake up the plants?

Kenny Grows

Kenny Grows

Active Member
I recently built a supplemental light that is only 720nm. I'm wondering if I should turn it on 15-10 mins before and after the normal lights come on. Or just have it on 15-10 mins after the lights go out. Any feedback is much appreciate?
 
Axion42

Axion42

Well-Known Member
I was told by some veteran growers here that if your main lights have a good red spectrum the waking up part isnt necessary, only running for 5-10 mins at lights out to put to sleep is the important part.
 
Rocket Soul

Rocket Soul

Well-Known Member
There are ways of calcultating how much time of end of day far red. They need around 3000-4000 umols (not ppfd) to change over. If you were running around 10w per square meter at around 2.5 ppf/w (giving 25 umols/second) youd need 4000/25= 160 seconds of far red with no other light. If you go over youll start seeing stretch. Ymmv
 
Kenny Grows

Kenny Grows

Active Member
captainmorgan said:
We're not splitting the atom here lol. For a phytochrome trigger 1 watt of quality 730nm will cover 10 sq/ft when left on for 5 minutes after lights out.
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Ok. If I want the Emerson effect also, how many watts per sqft?
I have 19W spread across 32spft (a 8*4 tent)
 
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captainmorgan

captainmorgan

Well-Known Member
The trigger is not needed in veg, you can run lights 24/0. Cannabis flowering is controlled by the length of darkness. Typically outdoors plants start flowering at 14 of light and 10 hours of dark because 730 is present. Indoors without 730 as a trigger the plant needs 12/12 because it takes the plant two hours to transition from awake to sleep. Adding the 730 trigger at lights out make the transition in 5 minutes so you can flower indoors up to 14/10. More light energy into the plant means more growth and higher yield.
 
ANC

ANC

Well-Known Member
I'm pretty keen (more keen than running 660), to try the 730 thing. I would imagine a monostable flip flop connected to an LDR or some other light sensor, should work well, I suppose it is just as easy to sense when power is cut in the main driver for the same purpose but would negate the need for calibration.

I honestly think the majority of 660nm implementations are a gimmick.
I'll test it in a grow off some time, but I have never felt the need for extra spectrum even on LM561C, if there are gains, I am sure it is minimal in real-world conditions.

FOr the cost of only a few diodes I can add a whole strip of F-series or H_Influx

I would like the ability to run a longer day as was alluded to above
 
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nachooo

nachooo

Well-Known Member
captainmorgan said:
What do you base this on? How long have you used 730nm in your garden?
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I have been using far red for several years… I dont remember exactly.. probably about 6 years. I had very good results and also crazy elongations...but always for timer malfunctions or using the far red in a wrong way. Initially I used too much althought the leds were epistar ones.. right now I am using oslon osram. Now I agree I need less watts per square meter I started with about 15 watts 15 minutes 1 square meter.. which is a lot!!! Now I use much less power ...Randomblame gave good info in the Far red threat he posted about far red doses:
https://www.rollitup.org/t/the-far-red-thread.867665/page-69

For me is about 5 watts in 4/5 minutes in a square meter (about 9/10 square feet)

Also..distribute only a 1 watt of led light over 10 square feet is somekind difficult…..I use about 12 leds at very low current ...to cover same área.with not hot spots of far red but I use now about 5 watts in 4/5 minutes

I use far red as EOD treatment mainly in two scenarios: Increasing light hours with short early indicas in order to improve production and decreasing light hours to shorten flowering time in sativas.

I have used it in veg also but nowadays I use it only in flowering after the strecht in the sativas and all the flowering with the indicas

I also use far red during day time to improve photosyntesis and stomatal behaviour but only when I add 2 or 3 more wattage with 660 nm leds.. If I do not add the 660...A few watts of far red mixed with my 3500k 80 cri samsungs gives me elongation… So all has to be carefully mixed.
 
captainmorgan

captainmorgan

Well-Known Member
I've been using and posting about 730nm in this forum section for probably 6 years and only know one person using 730 on this forum before me and he only made a couple of posts about it in a grow journal. The 1 watt per 10 sq/ft is enough to do the job as a trigger with a quality 730nm, I know this from experience.
 
nachooo

nachooo

Well-Known Member
captainmorgan said:
I've been using and posting about 730nm in this forum section for probably 6 years and only know one person using 730 on this forum before me and he only made a couple of posts about it in a grow journal. The 1 watt per 10 sq/ft is enough to do the job as a trigger with a quality 730nm, I know this from experience.
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Well..this is not a competition of any kind for me, and.this is just a place to share ideas...regarding the use of far red I just have found a post about it in this forum I did 5 years ago...well not a post from 6 years ago..my mistake...althought I used Far reds before the post..Still I think is better to use more watts...and if 1 watt Works for you ... is ok.. I just wrote my opinión.
 
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