- Sep 7, 2016
- Reaction score
Awesome have quite some experimentation in to this my self... I have height restrictionsSo here’s where you can help. I’m asking for each of you who have had successful grows under LED lighting to provide some basic statistics on your grow. I’m not trying to be rude by restricting this to successful grows. But I do need to acknowledge MedGrower’s point that there are other factors affecting plant growth, and eliminate those from the equation. So if something went bad on your grow - heat, nutes, bugs, pH drift not controlled, your room mate smoked it all when you weren’t looking - whatever - please defer posting until you complete a successful grow. Here’s what I’m looking for:
What is the breeder & strain and final cured yield of the plant you are reporting
Watts per sq. ft. documented from wattage-at-the-wall of your light(s) and with size and square footage of your grow area (size to identify odd shaped areas). If you use multiple lights, list each with a total wattage consumed.
Finished height or plant length. Difference being a measure of training effectiveness to final height. For example, if you took a 30” tall plant and brought her down to 12” with LST, then report total plant length at 30”. Remember, I want to measure stretch, more so than final plant height. The simplest method to measure stretch of a trained plant is with a string following the contour of the main trunk from base to tip.)
If you did no training & allowed the plant to follow its natural form, report No Training and normal plant height.
And finally, the magic sauce –
What light heights did you maintain throughout veg, transition and bloom? Ranges fine, for example:
Veg – start @ 30”, down to 16”,
Transition – start @ 16”, down to 12” (I frequently skip this, feel free to as well)
Bloom –maintained at 12” throughout bloom.
I don’t care if you raised the light to finish final bloom.
And maybe I should care about at what age the plant stopped growing vertically? Of all the info I gathered during my auto grows, I never thought to document that. If you did, report it.
As your reports come in, I will try to summarize these on the next post in table form, and maintain a running average of light height to plant height. If I find that’s not working out or for unknown reasons just not making sense, I’ll find some way to summarize & report your results. I’ll attempt to maintain that table by editing my thread post immediately following this.
Thanks for bearing with me, I know it’s a long start for this thread. If you don’t know yet, there are two things about me – I won’t do anything half-assed, and I don’t know how to write short posts
01 - Maple Shurbet x pre 89 skunk (photo) by seedstockers
02 - on average about 40w per square foot
03 - No training just trellis netting with the odd tie down / super crop... I let them get to about 15" to 20" before I flower them, I go by % on the stretch, my findings are below.
04 - Veg...T5 up until 2 weeks before flower, then 50w of led COB's for the 2 weeks before moving into the flower tent
Flower... 380w led COB's, 2 lights, one at 1400ma and the other 1050ma.
05 - light hight... I let them grow towards it, they can reach 5" in places... super cropping is used
Just my thoughts on this subject... This has been something that has interested me from the start due to my hight restrictions and I've done quite a lot of experiments, not as science as yours, more observational. Both with "burple" LED's and full white spectrum LED's.
My stats -
Tent... 117cm x 87cm x 145cm
Light... about 380w of DIY COB power
system... run to waste feeding every 24hrs
So far my findings are that light intensity and hang hight make no difference to stretch, I've been playing around with this for 2 years now... what I have found out and makes a massive difference in stretch is heat. I've seen and come to the conclusion with clones over this summer (its been a hot one in my loft garden)... Your old HID lighting projects more heat down, LED project more heat up, something to consider in you findings.
3 grows in a row with the same clones, starting in spring and the third and final grow is now into week 5... first grow about 60% stretch ambient temps of 24-25c, they reached on average about 15" to 10" from the light... 2nd grow (peek of the summer), easy 100%+ stretch with plenty of super cropping, ambient temps of 29c -31c, on average 5" from the light with quite a few needing super cropping as they grew into the light... 3rd grow 60%, ambient temps 25c - 28c back to 12" to 8" ( I did scrog this grow due to the last being so out of control which did effect the stretch on a couple of the plants but didn't hinder others)... the lights have been in a fixed potions at the top of the tent for all 3 grows.
I also have another tent of the same size (clones) with 455w of COB / Quantum board power driven 1050ma and are seeing the same results in there with heat over light intensity.. that light is like the sun, super bright and way over powered for the space.
This is just a personal opinion and from my observations but I think genetics / ambient heat / RH make all the difference in stretch and not so much light hight... that's not saying spectrum doesn't play a part in all this as we know the burple LED's light like to make those nodes spacing tighter.