Seedlings: Not enough light or too much?

D

DexterC

Well-Known Member
Hey guys!

So few days ago I started a White Widow and a Dark Phoenyx by Green House Seed Company in my 80x80(2.6ft) grow tent under a Viparspectra P2000. According to spec sheet this can take 120x120(4ft) from seed to harvest but I won't bet my butt on that. Anyway, I take precautions and keep it dimmed down to 5% for seedling stage and quite high, about 1m(3.2ft) away because lower it seems they don't like it. I find that at current set up the Viparspectra pushes about as much light as an LED bulb 6500k. I don't want to use bulbs tho. The problem is that the seedlings keep bending to the side like they try to get away from the light. But in the same time, I get a stretch that I am not comforable with. Not sure if the light is too low or too much really. There is no burn issues as temps stay really nice around 23-25C and RH between 65-75%. Environment will be on point even if I push lights to 100%. ( tested before planted the seeds). Medium is completely organic with a light mix for seed starting (Compost, Worm Castings and a bit of bone meal on a peat base). Mix was watered a werk prior to planting and left to activate. What could be up? Or I am worrying for nothing?

20220119_144021.jpg
 
DexterC said:
Hey guys!

So few days ago I started a White Widow and a Dark Phoenyx by Green House Seed Company in my 80x80(2.6ft) grow tent under a Viparspectra P2000. According to spec sheet this can take 120x120(4ft) from seed to harvest but I won't bet my butt on that. Anyway, I take precautions and keep it dimmed down to 5% for seedling stage and quite high, about 1m(3.2ft) away because lower it seems they don't like it. I find that at current set up the Viparspectra pushes about as much light as an LED bulb 6500k. I don't want to use those tho. The problem is that the seedlings keep bending to the side like they try to get away from the light. But in the same time, I get a stretch that I am not comforable with.
Click to expand...
Hey @DexterC hope your having a good day my friend.
Do you have a t5 fluorescent light.
Babies don't like led's until they get a bit bigger

Stay safe
Bill
 
DexterC said:
Hey guys!

So few days ago I started a White Widow and a Dark Phoenyx by Green House Seed Company in my 80x80(2.6ft) grow tent under a Viparspectra P2000. According to spec sheet this can take 120x120(4ft) from seed to harvest but I won't bet my butt on that. Anyway, I take precautions and keep it dimmed down to 5% for seedling stage and quite high, about 1m(3.2ft) away because lower it seems they don't like it. I find that at current set up the Viparspectra pushes about as much light as an LED bulb 6500k. I don't want to use bulbs tho. The problem is that the seedlings keep bending to the side like they try to get away from the light. But in the same time, I get a stretch that I am not comforable with. Not sure if the light is too low or too much really. There is no burn issues as temps stay really nice around 23-25C and RH between 65-75%. Environment will be on point even if I push lights to 100%. ( tested before planted the seeds). Medium is completely organic with a light mix for seed starting (Compost, Worm Castings and a bit of bone meal on a peat base). Mix was watered a werk prior to planting and left to activate. What could be up? Or I am worrying for nothing?

20220119_144021.jpg
Click to expand...

I've got a Viparspectra XS2000 in the same size tent. Get yourself a cheap lux meter on Amazon (mine's a Urceri and about $29). Use it to set your seedlings at 15k lux. After they get a few sets of fan leaves, 30k lux, when they get about 4-5 nodes of fans, 50k. Full bloom about 60k. It should keep them bushy yet not so much light that they get damage.
 
Bill284 said:
Hey @DexterC hope your having a good day my friend.
Do you have a t5 fluorescent light.
Babies don't like led's until they get a bit bigger

Stay safe
Bill
Click to expand...
Hey Bill, thanks for the quick reply. I have a few options but I wanted to avoid using them. Company says that light is good for seedlings too.

farside05 said:
I've got a Viparspectra XS2000 in the same size tent. Get yourself a cheap lux meter on Amazon (mine's a Urceri and about $29). Use it to set your seedlings at 15k lux. After they get a few sets of fan leaves, 30k lux, when they get about 4-5 nodes of fans, 50k. Full bloom about 60k. It should keep them bushy yet not so much light that they get damage.
Click to expand...
I used an app and my phone sensor. Nothing accurate, but usefull to get a point of reference. So from what you are saying I understand you have the xs2000 at around 50-60% to get 15k lux. I am only giving them about 3-4k lux. Maybe that's the problem. They need more, hence the stretch too.
 
if they stretch meaning ligh to far away - if your seedling is to tall re-plant it deeper leaving 1/2 inch above soil to top of plant -- then make light adjustments your 2,000 is a very strong light you need to dim it to 50% till you have 3 sets fo true leaves
 
Hiya - you ideally want blue light on seedlings, but she will be fine once she's put some roots down and remember WW is a hungry fker so don't be shy with the N/K
Don't worry pal
 
safeman said:
if they stretch meaning ligh to far away - if your seedling is to tall re-plant it deeper leaving 1/2 inch above soil to top of plant -- then make light adjustments your 2,000 is a very strong light you need to dim it to 50% till you have 3 sets fo true leaves
Click to expand...
Got it now, I was having it dimmed too much. It was down to 5-10% and I keep it about 1m. away, @farside05 says the same. I changed it to about 55% at same distance. We'll see how they respond.
 
Growings said:
Hiya - you ideally want blue light on seedlings, but she will be fine once she's put some roots down and remember WW is a hungry fker so don't be shy with the N/K
Don't worry pal
Click to expand...
Viparspectra pushes mostly white light. I've seen some nice results under this light, not worried about quality. As for plants, They are in organic medium, quite rich. Bone meal should give them a nice steady supply of NP as it takes a while to break down but I'll add something more rich in N if I get issues down the road. Good to know, never grew White Widow before or smoked. I can't wait to see how she turns out. Thanks for advice, maybe I'll be able to get away without defficiencies knowing she's heavy feeder.
 
DexterC said:
I used an app and my phone sensor. Nothing accurate, but usefull to get a point of reference. So from what you are saying I understand you have the xs2000 at around 50-60% to get 15k lux. I am only giving them about 3-4k lux. Maybe that's the problem. They need more, hence the str and etch too.
Click to expand...

Phone light meters apps are highly inaccurate. I've done 2 different comparisons about 2 years apart. They are located HERE and HERE. It's well worth the $30 spent on a real meter if you're wanting to get the most out of your light.

HERE is a link on how to use a lux meter for cannabis. I tend to give my seedlings a bit more light than the article. They may be a bit shy for a couple days but they get accustomed quick and it keeps them from stretching. Above 60-65k I've seen some light damage so i usually cut it off there.
 
Okay! Problem solved. Little ones already respondend and oriented towards the light.

20220119_154921.jpg


I figure the reason for bending was due to light reflection. As light reflects in the tent, it creates 4 bright spots on the sides of the tent where more light rays come together and create a more intense spot than the light itself. This happens because light was not pushing enough. It's more complicated than that of course but I hope it makes sense. That's my assumption at least, did not test that yet. That's why the little ones were bending and stretching ... and only towards those spots.
20220119_155812.jpg

(Excuse my drawing skills. Never liked it.)

Anyways, thanks guys! You really helped, as usual! :)
 
DexterC said:
Okay! Problem solved. Little ones already respondend and oriented towards the light.

20220119_154921.jpg


I figure the reason for bending was due to light reflection. As light reflects in the tent, it creates 4 bright spots on the sides of the tent where more light rays come together and create a more intense spot than the light itself. This happens because light was not pushing enough. It's more complicated than that of course but I hope it makes sense. That's my assumption at least, did not test that yet. That's why the little ones were bending and stretching ... and only towards those spots.
20220119_155812.jpg

(Excuse my drawing skills. Never liked it.)

Anyways, thanks guys! You really helped, as usual! :)
Click to expand...

Wow, in just an hours time!
 
farside05 said:
Phone light meters apps are highly inaccurate. I've done 2 different comparisons about 2 years apart. They are located HERE and HERE. It's well worth the $30 spent on a real meter if you're wanting to get the most out of your light.

HERE is a link on how to use a lux meter for cannabis. I tend to give my seedlings a bit more light than the article. They may be a bit shy for a couple days but they get accustomed quick and it keeps them from stretching. Above 60-65k I've seen some light damage so i usually cut it off there.
Click to expand...
I'll buy a proper meter with a quantum sensor sometime in the future. I'll need that for other projects as well. In the mean time I figure I'll just find the sweet spots for this light and stick to those. I'd rather pay a few hundreds once and have them spent well. Of course in your case that kind of investment may not make sense, but I'm as much as a nerd as I am a stoner
 
DexterC said:
Of course in your case that kind of investment may not make sense, but I'm as much as a nerd as I am a stoner
Click to expand...

I'm a nerd too but my area of nerdiness leans towards math and plant nutrition. I recently dropped $300 USD on mineral salts so that I could design my own nutrient line to my specs.
 
farside05 said:
I'm a nerd too but my area of nerdiness leans towards math and plant nutrition. I recently dropped $300 USD on mineral salts so that I could design my own nutrient line to my specs.
Click to expand...
Mine engineering and science. Working my way towards at least. That sounds awesome by the way. Hope it turns out great! I'll stick with basics there myself.
 
farside05 said:
Wow, in just an hours time!
Click to expand...
It is fascinating watching how fast some plants will respond. Supercrop a plant that is in the very early stage of flowering and the tips will start to point up toward the light within an hour, maybe two.

The longer the plant has been in flower the longer it takes to respond from what I have noticed but in the first week or two it is as if nothing will stop the plant.

Oh, and that is a real 'door stopper' of a plant shown in your other msg. Impressive.
 
DexterC said:
Damn... those nugs dwarf baseball bats good job dude. That's some monster bush you got there. But that's auto, right?
Click to expand...

I call it a N.A.A. (Non-Auto Auto). It was supposed to be. Northern Lights x Big Bud Auto. It never autoed so I finally had to flip her to 12/12 to get her to bloom. She's also been a notoriously slow bloomer. I think I flipped her back around October 20th?
 

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