Ive seen your buds, and theyre proof enough to know you do well... What are the signs of stress, that you notice?Haha sorry, I'm closer to Boulder.
The spacing on my flower fixture is 11.5" on center. Too close together for 1.4A and limited heighth. I'd have been better off running them at 1.05A and been able to dim them more from that current.
COBs distance from canopy
- Thread starter GreenSanta
- Start date
Yodaweed
Well-Known Member
I think it depends on how hard you drive them, do you have a lux or par meter @GreenSanta ? If not start around 20 inches and if thats too intense (leafs fade quickly or bleach) then move it up. Happy Growing.
I also think optics like reflectors or lenses has to do with how high you can hang them. If you use a diffuser it will be able to be closer
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MeGaKiLlErMaN
Well-Known Member
It's best for efficiency of photosynthesis, that said I'm running 1200ppfd in a 4x4 at 12-6". No light bleaching, no stress. Check my signature.. Especially the temp that also is just as important as light. 75F at 1000ppfd is the same as 500ppfd at 86F. Something to think about.
cdgmoney250
Well-Known Member
Thanks man!
IME, the plants will start to exhibit signs of deficiencies like Mag, Cal, Phos, N, Iron or even Zinc (or bleaching like Yoda said), but only in the areas of the plant that are over saturated with light, such as the upper growth. The growth will seem happy and healthy in areas of lower light intensity. Over saturation can lead to photoinhibition, which substantially reduces photosynthetic efficiency.
There are quite a few variables that will effect how much light a plant can actually use. Therefore, the maximum light intensity plants can handle may be different in different environments. Just my opinion.
theslipperbandit
Well-Known Member
Id my cx-16 first at the 3 foot suggestion now im trying 4ft and the seem pleased
CobKits
Well-Known Member
there are a whole lot of variables youre not considering, such as open space or reflective walls? bare cobs or lenses or reflectors? number and spacing of cobs?, etc
the best results for any garden is going to be the height that is closest to the plants which illuminates the canopy *uniformly*. if you have dark spots alternating with bright spots because your cobs are too close that is not helping anything. if your light is uniform over your canopy at a given height and a proper PPFD, raising it further wont help either
KonopCh
Well-Known Member
Didn't you see that I wrote "the same enviroment, but only different distance to canopy"?
CobKits
Well-Known Member
i sure did. my point is some else's environment is not the same at your environment, so trying to translate other people's results to your space will not be super useful, do you have a basic light meter? thats really all you need to dial in your space. even if its not reading par the plants will tell you what intensitty they like, and the meter will tell you how uniform that intensity is.
KonopCh
Well-Known Member
I am not asking for help. I have my lights at 40cm above canopy and I am happy with that. But I grow autoflowers.
I was asking simply because you guys here grow photos and can take clones for my simple asked test/question. That will show us some more real world data, not only "PPFD, uniformity, calculations, photons at canopy, wattage, inverse square law" etc... But practice!
Muskegman
Well-Known Member
You dim your lights down all the way and still get that much PAR? I’m running the timber grow lifts 600 watt, 6 Vero29g7. On the frame timber provided. Two drivers. What height would you hang them? I have mine at 20 inches right now
Randomblame
Well-Known Member
Mate, that's an old thread. Don't be surprised when you get no answer.. at least not from him. Have not seen him since a good while.
The Timber 600w produce a hell lot of light. 60cm/24" should work but it depends also on your grow area.
Is it a tent or open space?
A 4' x 4' or 5' x 5'?
It is not the distance what cause bleaching, it's the intensity.
If you can get a cheap lux-meter from e3ay or am4zon, get one(12-15$, smartphone apps are no accurate enough).
50.000lx are around 750-800μMol/s and that's a good range to keep your plants happy.
But it depends also on grower skills.
With higher intensities it get's more difficult to keep the plants healthy. To keep 85°F/30°C with ~60% humidity is more difficult the higher the intensity goes. Above 800-1000μMol/s PPFD you also need additional CO² so the plants can realy profit from higher light intensity.
For that reasons I recommend always a target intensity of 700-800μMol/s/m². The Timber 600w can probably hit this numbers over a 5x5' or 5x 4' area but need's at least 20-24" to get nice and even measurings across your area.
Muskegman
Well-Known Member
Mate, that's an old thread. Don't be surprised when you get no answer.. at least not from him. Have not seen him since a good while.
The Timber 600w produce a hell lot of light. 60cm/24" should work but it depends also on your grow area.
Is it a tent or open space?
A 4' x 4' or 5' x 5'?
It is not the distance what cause bleaching, it's the intensity.
If you can get a cheap lux-meter from e3ay or am4zon, get one(12-15$, smartphone apps are no accurate enough).
50.000lx are around 750-800μMol/s and that's a good range to keep your plants happy.
But it depends also on grower skills.
With higher intensities it get's more difficult to keep the plants healthy. To keep 85°F/30°C with ~60% humidity is more difficult the higher the intensity goes. Above 800-1000μMol/s PPFD you also need additional CO² so the plants can realy profit from higher light intensity.
For that reasons I recommend always a target intensity of 700-800μMol/s/m². The Timber 600w can probably hit this numbers over a 5x5' or 5x 4' area but need's at least 20-24" to get nice and even measurings across your area.[/QUO
Thanks man I just saw this was that old of a thread. I’m growing in a 4x8 tent with the timber on one half and a different lift on the other. I’m growing 8 plants all together with four on each half of the tent. RH is set at 60
And so far I’ve been able to keep the temps in the mid 70’s light on and high 60’s lights out. I was keeping the lights at around 12 inches from the canopy with no ill affects but figured I better raise them and I wanted to cover more of the outside edge of my plants, so it’s up higher now at 20 inches actually. I’m growing in soil and not supplementing with CO2. I’m ordering a PPFD meter today so I know where I’m at. Honestly I’ve never used the dimmer one time, and never understood why in the world I’d want to dim the lights unless my plants were growing too tall and had to so they wouldn’t burn. If I can turn them down and still get at least 600-700 PPFD then that would be amazing . I’ll let you know and I appreciate you input. Here’s what they look like last night, day 34 of flower.
I know this is an older thread but I am finding that too close 18-24” during veg and with reflectors can sometimes make me think I’m getting defiencies.
If I dim or raise the cobs they are much happier.
I’m running 9 cxb 3590 in a 3.5 sq at 1.4amps which if I remember was around 900uMol/m2.
Mine run at 51watts per cob or approximately 51watts per sq foot which is gobs and plenty.
If I dim or raise the cobs they are much happier.
I’m running 9 cxb 3590 in a 3.5 sq at 1.4amps which if I remember was around 900uMol/m2.
Mine run at 51watts per cob or approximately 51watts per sq foot which is gobs and plenty.
OLD MOTHER SATIVA
Well-Known Member
i had that problem with my 3590's too
i removed the lenses and the reflectors
i can get close now and none of the "deficiency" look either..i do not dim
i removed the lenses and the reflectors
i can get close now and none of the "deficiency" look either..i do not dim
What power you running through your cobs?
I've heard many are either removing reflector or getting lenses to help diffuse but your saying you have found not using any type of lens and reflector?
I mainly wanted to use a lens to protect cobs from dirt,moisture,water when foliar feeding but I have heard cobs can be wiped off with alcohol and aren't as damaged by water spots??
I'm glad they leave these threads up, even old this has been very helpful. Since I added another 300w COB Led to my flower room I started having CAL/MG def &/or bleaching/burning issues that I've never had before and I couldn't seem to figure it out. It seems they can show deficiencies when I really just needed to raise the lights a bit on them even though not a heat issue. Most all opinions/experiences are thoughtful and helpful. I try to take all information and use it to show patterns and general guidelines since we all know there are so many variables no 'one' way is always right. Thanks All.