LEDs and height
- Thread starter trixP
- Start date
oldmaninbc
Well-known member
I have wondered about the hanging height myself, so far I have followed the hanging instructions suggested by Viparspectra. In bloom I have gone a bit lower as I have a limited growing height of 28".
36"-40" seedlings...after a week or two down to 24" for veg
15'-18" bloom, I have gone down to 12" or so.
I have ran 2 different LED lights...357 Magnum was the first it never came with instructions, my memory is not as good as it use to be and I don't recall the hanging height, that was maybe 4 years ago. I have run the Viperspectra for four years now. Perhaps newer lights come with a different instruction or people make up their own.
trixP
Active member
I was originally gona keep my girls in veg and clone them out things changed, I stayed low as usual so they would ant stretch and run out of room, I’m week 4 flwr and have room as I said I raise 3/4 clicks on the ratchets no more
I have a meter so I am always lowest watts for highest ppfd
I have a meter so I am always lowest watts for highest ppfd
Terpyterps
Active member
I push my lights at mid to later flower at 8-12 inch or 20/30 cm. Had to move them up at early flower because they showed bit stress from too much light, although I introduced another 150w at the same time, so no wonder they did. At the moment they are at 12 inches away from tops, did LST so the canopy is super even so they are receiving pretty much evenly light and no signs from light stress, just few girls are having signs from the first light stress. But also there is pretty fine line when you are getting closer to the plants what is too much and what is just perfect amount of light, this might be why some run theirs way up, so they don’t have to stay on top of the plants all the time. Personally I am there every day checking what’s up with everything and keep eye on light stress, but I am also at mid flower so no stretching anymore so it’s not like they would be climbing to the light fixture. At stretch phase I just rise the fixture up to 16-18 inches so they are free to do their thing. If you just provide strong enough nutrition for the plants then it’s pretty safe to push the lights also closer.
Running now two Mars Hydro TS-1000 LEDs, but going to get Mars Hydro FC-4000 EVO for next run for my ladies so I can spare newer of those TS-1000 to my mom/cutting tent.
Running now two Mars Hydro TS-1000 LEDs, but going to get Mars Hydro FC-4000 EVO for next run for my ladies so I can spare newer of those TS-1000 to my mom/cutting tent.
Terpyterps
Active member
One thing to bear in the mind is that Quantum Board LEDs doesn’t have very good spread of light so keeping them higher helps with the spread. Bar fixtures have excellent spread if it is correct size and shape for the tent and it would not be a problem.
trixP
Active member
I LOVE m’y rayonLED 760 i also have the 400 veg spec
These lights are a big pet of my success, the 400 everything they say about it on the site it does
CRAZY tight nodes, structure etc
I actuslly the 760pro
Lowered my light 3 clicks the other day
680w full spec+2x40w UV FR running wide open
Trying to get my shorter girl to catch up
The shorter ones buds are way way fatter like crazy fat red bull cans easy easy my taller girl is frostier however
Week 6 of 9/10 and I’m expected early harvest due to the UVs
Love running a controller for the light life is so much easier
I’m flexing 850-1200ppfd from corners to the middle
Running 615w on the full spectrums and 100% on the uv fr
These lights are a big pet of my success, the 400 everything they say about it on the site it does
CRAZY tight nodes, structure etc
I actuslly the 760pro
Lowered my light 3 clicks the other day
680w full spec+2x40w UV FR running wide open
Trying to get my shorter girl to catch up
The shorter ones buds are way way fatter like crazy fat red bull cans easy easy my taller girl is frostier however
Week 6 of 9/10 and I’m expected early harvest due to the UVs
Love running a controller for the light life is so much easier
I’m flexing 850-1200ppfd from corners to the middle
Running 615w on the full spectrums and 100% on the uv fr
Terpyterps
Active member
Yup. I am pretty much max out PAR vice because two ts-1000 produce pretty much point on for 2x4 requirements. Just wanted to get FC-4000 EVO that has 320w and better coverage than those that I have now. But PAR vice no need really for new fixture yet. You can always pump up nutrients if they are taking a damage from light because they need more energy for photosynthesis and for that process plants need nutrients. It’s very unintuitive but when you think about it, it makes sense, but not with tiny plants because they have tiny roots.
I snapped accidentally just before my autos were switching to flower my Sticky Orange XXL’s main stem, but there is nothing that little bit duct tape wouldn’t fix and it is just week or week and a half behind the others and might be due to it being XXL. But it’s one thing that I learned last summer growing autos outdoors that they can take a beating anytime and bounce back like nothing. Had problems with deer and moose etc. they did mostly my topping for me.
I snapped accidentally just before my autos were switching to flower my Sticky Orange XXL’s main stem, but there is nothing that little bit duct tape wouldn’t fix and it is just week or week and a half behind the others and might be due to it being XXL. But it’s one thing that I learned last summer growing autos outdoors that they can take a beating anytime and bounce back like nothing. Had problems with deer and moose etc. they did mostly my topping for me.
Terpyterps
Active member
And with snapping I ment that it felt catastrophic when happened, but there is no damage what cannabis plants won’t fix if just attached back to the original place. Had just sliver of skin and stem there. Heck I have seen people crafting cannabis cultivars one to another! Although only possible with photoperiodic plants because their lifespan.
Terpyterps
Active member
Also I am pretty happy after I could change from HPS to LED without missing anything. Rather battle with too cold and some nutrient need changes than with their humongous heat issue and efficiency in converting electricity into photons for the plants. Mars Hydro TS-1000 convinced me to change, because I saw the potential in only 150w so I could figure out that bigger are even better.
trixP
Active member
Makes allot of sense, seedling I went 2 weeks just water and and first I didn’t go full gas on the nutes, I also went buck on the worm casting in my soil lol my girls were super dark lol, learnt allot already
i am running a mars fce8000 in a 5x5ft tent, around 70pct power - i don't understand how guys have their led's 30/36'' over the plant... u gotta be losing a shitload of the light- now keeping it too close, then the outside plants ain't getting enough light. there must be a happy medium..
trixP
Active member
How stretched are your girls
I've seen grows with LED hung a foot and a half to two feet with terrific results, but wouldn't doubt that 30" would be a bad height nearing the end of stretch.
Terpyterps
Active member
But also when talking about these LED fixtures that are pushing like 700w or more produces so high PAR ratings that you can run them way up too, not sure why to buy so strong LED if the potential is not used.
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not stretched much at all.... i didn't measure, but if i went 12/12 at 36'' (from the ground) , they probably ended up at maybe 42ish... same plant under a cmh prob would be hitting the roof of the tent...
Unless the leaves actually touch the light there is no burn.
I have 9 three gal pots in flower. I harvest one plant per week after 9 weeks in flower, and replace the harvested plant with a plant from veg side. There is variation in plant height as a result.
Jackberry within 1" of the LED in fifth week of flower.
You have some fine looking ladies man!
wow.. they r indeed nice looking plants... my 1st grow under led's last may, i had the light real close to some buds, maybe 12inches, n some, not all dried out... they were crispy...
X15
Well-known member
I still run an older model Spectrum King LED. I also use a light mover. I will keep it around 24-30 inches above the canopy but have had it as close as 12 inches. I have not noticed any benefits from 12 inches vs 24. My room does not have ac so there’s been times the room has gotten a bit warm for the plants liking with the light closer than 24”… I like to bet on the safer side and keep it higher. I don’t grow for yield tho, simply for taste and effect.
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