Lighting Too much light?

[4d-Rock]

Hey all,
I’ve started a new grow recently and have several light configuration choices for my 3x2’ tent.

For this one I decided to try out 3 of my homemade COB lights (55w/each) at 20/4.
Here’s what they look like, though I’ve added the 3rd since taking the picture.

They are currently around 30” from the seedlings which gives between 15-17k lux across the canopy.
Is this too much light? They are a bit slow going and one is getting some leaf twist, though I’ve seen that before with no Ill effect.
Here they are at day 7

And the twisty one.

If I turn off the middle COB, I get about 10-12k lux, just wondering if that’s a better route for this early stage.
Thanks

 

[karlkutta]

at the seedling stage this might be overkill even if you have them 30" up. but also keep in mind they are developing their roots at this point and I feel like it takes up to week 2-3 for them to really start moving and pushing out leaves.

 

[Olderfart]

Hey all,
I’ve started a new grow recently and have several light configuration choices for my 3x2’ tent.

For this one I decided to try out 3 of my homemade COB lights (55w/each) at 20/4.
Here’s what they look like, though I’ve added the 3rd since taking the picture.
View attachment 1238858

They are currently around 30” from the seedlings which gives between 15-17k lux across the canopy.
Is this too much light? They are a bit slow going and one is getting some leaf twist, though I’ve seen that before with no Ill effect.
Here they are at day 7
View attachment 1238859

And the twisty one.
View attachment 1238860

If I turn off the middle COB, I get about 10-12k lux, just wondering if that’s a better route for this early stage.
Thanks

They look reasonably happy to me, so I think you would be ok either way - middle one off, or on - but I am new at this. I suggest that if you stay with all three, just watch for the beginning of tacoing and back off if you see it.

 

[Death The Cultivator]

Hey all,
I’ve started a new grow recently and have several light configuration choices for my 3x2’ tent.

For this one I decided to try out 3 of my homemade COB lights (55w/each) at 20/4.
Here’s what they look like, though I’ve added the 3rd since taking the picture.
View attachment 1238858

They are currently around 30” from the seedlings which gives between 15-17k lux across the canopy.
Is this too much light? They are a bit slow going and one is getting some leaf twist, though I’ve seen that before with no Ill effect.
Here they are at day 7
View attachment 1238859

And the twisty one.
View attachment 1238860

If I turn off the middle COB, I get about 10-12k lux, just wondering if that’s a better route for this early stage.
Thanks

Can you dim them? I dim my lights and gradually increase the output.

 

[Arthur]

A lot of light for such small ladies. I run diy cobs, 50w ea. 9 in a 4x4 tent. At this stage, I would be dialed way back. When I run a full 4x, I have 5 off and the other 4 at the lowest setting, about 40% power. I'm not at full power across all till a bit after sexing.

 

[4d-Rock]

Thanks all for the input
@damien50 unfortunately these are all or nothing. No way of dimming, but I think I’ll turn off the center one and see how they go.

My last grow I was limited for space and had 3 under one single COB and it seemed to go well, here is what they looked like at about the same age.

I just see many other peoples journals that seem to have their plants growing at 2x the speed as mine. Thought maybe I wasn’t giving enough light so I went with 3 to start. Guess that may not be the issue. I think my tent environment is decent.
23-24C daytime, 19C night, ranging from 50-60RH

 

[Arthur]

Thanks all for the input
@damien50 unfortunately these are all or nothing. No way of dimming, but I think I’ll turn off the center one and see how they go.

My last grow I was limited for space and had 3 under one single COB and it seemed to go well, here is what they looked like at about the same age.
View attachment 1238876

I just see many other peoples journals that seem to have their plants growing at 2x the speed as mine. Thought maybe I wasn’t giving enough light so I went with 3 to start. Guess that may not be the issue. I think my tent environment is decent.
23-24C daytime, 19C night, ranging from 50-60RH

What your seeing is other people starting their count at different spots. Some count from germination, some from sprout, some from first true leaves. First true leaves is about 2 weeks from germination, so many see a "two week" old plant and don't take in to consideration that the guy counts from first true leaves and its actually closer to 3 and a half. Also different setups, and grow styles will affect it some, as does environment, but I know a lot of new, or new to autos, miss the count early on.

 

[Death The Cultivator]

Thanks all for the input
@damien50 unfortunately these are all or nothing. No way of dimming, but I think I’ll turn off the center one and see how they go.

My last grow I was limited for space and had 3 under one single COB and it seemed to go well, here is what they looked like at about the same age.
View attachment 1238876

I just see many other peoples journals that seem to have their plants growing at 2x the speed as mine. Thought maybe I wasn’t giving enough light so I went with 3 to start. Guess that may not be the issue. I think my tent environment is decent.
23-24C daytime, 19C night, ranging from 50-60RH

What might be the most helpful in your situation is to rent a PAR meter and take measurements at 12/18/24/30/36/42 inches. Map your numbers and then you'll have a baseline to work with. You'll know exactly what you need/have.

You could also get a different driver with dimming capabilities.

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[Mañ'O'Green]

The idea that you are giving your seedlings too much light is not founded on science. The sun does not have a dimmer and seedlings don't die because of too much light. Lights can be too hot (IR heat) and physically burn a plant that is too close but just bright light will not harm them.

 

[4d-Rock]

@Arthur That is true that people have different starting points for counting. I basically call day 1 when it is fully above ground.

@damien50 that’s a good suggestion, I don’t think I need to be that precise though. I do change combination of different lights in each grow so it’s not always consistent.

@Mañ'O'Green ahhh, I think I get what you’re saying. so then if the seedling isn’t too hot or bombarded with too much infrared, it should be able to utilize as much light as it can regardless of it being over that amount?

I guess then in this case, it’s not too hot at 24C, and i may be wrong but I think COBs spectrums don’t include infrared, so adding the 3rd light couldn’t have a detrimental affect?

...or am I just high?