Does Red light matter with auto flowering strains

[JohnnyBravo]

I am considering an auto flower strain for a 3 foot tall stealth grow box......is it necessary to switch over to 12 hour lighting during flowering or can you just leave lighting on 24/7 like when your vegging a plant......and do you have to switch over to red/hps bulbs or can you just continue 24/7 blue light.....thanks for any replies

 

[jartlow]

I am considering an auto flower strain for a 3 foot tall stealth grow box......is it necessary to switch over to 12 hour lighting during flowering or can you just leave lighting on 24/7 like when your vegging a plant......and do you have to switch over to red/hps bulbs or can you just continue 24/7 blue light.....thanks for any replies

I do 20/4 on autos. Seems to be a common ground between growers. The red spectrum is out of my league as I use an all white led.

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[kagecog]

I wouldn't leave your light on 24/7 at any growing stage because like humans, plants need some rest for optimal growth, even autoflowering strains. Like jartlow said, I would recommend a 20/4 light schedule. In reference to your color spectrum question, red spectrum is a needed aspect for the most efficient bud growth during flowering. Without enough red spectrum light, you could be loosing anywhere between 30-60% of your yield.

 

[condogg]

So for example I have 5 lamp leads and 10 cfl bulbs all 20 watts, 5 are 6500k and 5 are 2700k. I can use five at a time equalling 100watts but if I but dual splitters on all the lamp leads I can have all ten bulbs on at a time equalling 200 watt(more light is better but not too much, I understand) however I don't want them all on at the same time but would it be okay to have say five 20w 6500k bulbs and two 20w 2700k bulbs for veg stage and then 5 2700ks and two 6500k bulbs for flowering In order to get extra 40watts of energy for the plant each stage or would I be better sticking with the five correct bulbs for each stage?

I'm growing vast and fast feminised autos incase anyone is interested and currently germinating my first seed and will be doing a journal, I've started the first entry

 

[Dr. Who]

Like "flushing". The "need" for "red" lighting spectrum is very misunderstood in growing MM.......I never change from MH to HPS! I fell for that Hodo for awhile but, it never did as well as MH in almost every way! I even have found that HPS can lengthen the bloom period with long lights on times of 12/12 (this is another topic but, lighting for less then 12/12 is better and faster).........While nature does tend to shift a bit to a more "red" spectrum in the fall,,,,it in no way is a significant change, that requires you to shift to an HPS for more "red". The Hps does not make a comparable shift in that relationship anyway!

The plants use several forms of "red" spectrum in differing ways. In fact, it's better to even say that it use's 1 specific spectral range in the "red" to do one thing. That is the 730nm range used by the plant to "go to sleep".....This spectrum is exposed to the plant at close to the actual "night" or late dusk, right before true night. The plant takes 2 hrs to shut down from being exposed to minute amounts of this spectrum. For high dollars you can actually get an LED that use's only 730nm band light to expose your plant to it's spectrum for about 10min or so at the lights out time and it shuts the plant down in seconds as opposed to hrs.....Theory is you get 2 more hrs of lights on time to get more bloom growth....I have a cpl of these and I call them as not really giving me anything but 2 more hrs of electrical cost vs increased returns....Don't bother spending on this.

Now then, this 730nm band is supplied to your plants in the few moments of light shut down. Just the same as in nature....So then, your getting what is the "critical" red spectrum, when it's required......Why spend money on an HPS and a MH when you really only need the MH.....Like I said, the MH does a better spectral job overall then the HPS does even for the flowering period alone.
You get more UV range lighting from it also! Win, Win!!

Doc

So then, to answer your question.....NO, it's not needed and it's needs are supplied by your normal lighting when it needs it.....right on time!

 

[Dr. Who]

Yah know I wish I could take back that last statement.......That's more opinion then anything.......HPS should be used....I wish it had some more low nm blues though.....I do run a more full spectrum MH......I am most likely going to newer lamps of HPS in my new grows......I should have bought Gavita's.....HPS....and mixed in a little deep blue......Now a days, there are some REAL quality LED's coming out......low watt vs HID high watts that are getting very, very interesting! Yet for pure flower yields,,,,HPS will rule the day....for a few more years....

I'll go back to HPS on a few runs (no MH) and compare again.....My money leans (reluctantly) to the newer HPS bulbs over my old MH.....we'll see.
edit -
I went back in notes from a cpl of years ago when talking to prof Runkle (MSU)....In a nutshell....
HPS is almost 50% more efficient (electrically)
Delivery of usable PAR is better with HPS than metal halide (what makes plants grow).
HPS delivers up to 35% more lumins


A humbled
Doc

Now why did I change back to MH anyway? gett'in old dudes, gett'in old!

 

[Fease]

good info thx^^ a complete spectrum is always a good thing. When and how the plant uses it when they're awake is the plants business lol. Lets face it, light and how plants use it is more complicated then most of us know. I think I've read a hundred different well educated threads about light and all seemed equally valid and interesting to some extent.