Light stress without taco leaf?

[the123321]

I have a 240w kingbrite quantum board led 3500k with 660nm led on it. I am having a hard time dialing it in to the right power. I have a lux meter that is supposed to work with led and even when in flowering the light at like 80% power at like 24 inches from the top of the plants it looks like what may be light stress though it may be nutrient problems in the plants. There are some of the buds that have yellowing on leaves near the top of the plant and some of the lower buds do not have the yellowing though the leaves on the plants are not taco leaf.

Have you had light stress without taco leaf? The reason I ask is if light stress usually has taco leaf I will figure that the yellow is from nutrient problems in the plants and then likely turn the power on the light up to like 90% and try to get the lux near 50 - 60k at the top of the plants in flowering on there. I did not post images as I mainly want to find out if you have had light stress on plants without taco leaf on there.

 

[derek420colorado]

Do you have any pictures

 

[the123321]

Thanks. I did not post images as I mainly want to find out if you have had light stress on plants without taco leaf on there.

 

[derek420colorado]

Thanks. I did not post images as I mainly want to find out if you have had light stress on plants without taco leaf on there.

It is virtually impossible to tell what your issue is. Yes I have seen light stress without curling leaves in fact almost all is a discoloring that j have seen. Now are you talking about light stress or heat stress they are two totally different things. Hence the need for a picture. It is simply to try and help

 

[Animatey]

I have a 240w kingbrite quantum board led 3500k with 660nm led on it. I am having a hard time dialing it in to the right power. I have a lux meter that is supposed to work with led and even when in flowering the light at like 80% power at like 24 inches from the top of the plants it looks like what may be light stress though it may be nutrient problems in the plants. There are some of the buds that have yellowing on leaves near the top of the plant and some of the lower buds do not have the yellowing though the leaves on the plants are not taco leaf.

Have you had light stress without taco leaf? The reason I ask is if light stress usually has taco leaf I will figure that the yellow is from nutrient problems in the plants and then likely turn the power on the light up to like 90% and try to get the lux near 50 - 60k at the top of the plants in flowering on there. I did not post images as I mainly want to find out if you have had light stress on plants without taco leaf on there.

I'm not exactly sure what is up with some of my plants, but I see the top sets of leaves yellow around the edges without any tacoing. I'm pretty sure it's light related in one sense, in that the plant just can't take the light. Also my issue happens at 40k lux...

You might have a more complicated problem than just light stress. It could be light related, or exacerbated by light. Pictures would help others diagnose, but it can be tricky. Still not 100% what's causing mine, but it might be related to removing some airflow from the tent.

I've seen it in my last few crops after week 6 of flower.

 

[Mañ'O'Green]

I'm not exactly sure what is up with some of my plants, but I see the top sets of leaves yellow around the edges without any tacoing. I'm pretty sure it's light related in one sense, in that the plant just can't take the light. Also my issue happens at 40k lux...

View attachment 1211249

You might have a more complicated problem than just light stress. It could be light related, or exacerbated by light. Pictures would help others diagnose, but it can be tricky. Still not 100% what's causing mine, but it might be related to removing some airflow from the tent.

I've seen it in my last few crops after week 6 of flower.

That is the prettiest display of a potassium problem I have seen. The problem with potassium is a deficiency looks just like a toxic reaction?

IMPO Light burn looks more like brown crispy edges and bleached out bud tips.

 

[derek420colorado]

That is the prettiest display of a potassium problem I have seen. The problem with potassium is a deficiency looks just like a toxic reaction?

View attachment 1211254

IMPO Light burn looks more like brown crispy edges and bleached out bud tips.

I’ve seen this chart a bunch but just noticed the ideal k mg ca ratio. Good note!

 

[Animatey]

That is the prettiest display of a potassium problem I have seen. The problem with potassium is a deficiency looks just like a toxic reaction?

View attachment 1211254

IMPO Light burn looks more like brown crispy edges and bleached out bud tips.

It's weird though, it only seems to affect the top leaves. But you might be right, I honestly have no idea at this point.

On this plant you can see that it's only the upper most leaves. Everything below the top 2 nodes looks perfect. Which is why it seems to me light related.

I'm using the Dyna Gro line and it's possible Mg/Ca is locking out K but I have no idea.

I've been using Mag Pro at pretty low doses. Even less than 50% of the feed chart. I dunno, but I'm pretty stumped.

 

[Mañ'O'Green]

It's weird though, it only seems to affect the top leaves. But you might be right, I honestly have no idea at this point.

On this plant you can see that it's only the upper most leaves. Everything below the top 2 nodes looks perfect. Which is why it seems to me light related.

View attachment 1211255

I'm using the Dyna Gro line and it's possible Mg/Ca is locking out K but I have no idea.

I've been using Mag Pro at pretty low doses. Even less than 50% of the feed chart. I dunno, but I'm pretty stumped.

I have a plant that looks worse than yours. I feed six plants out of the same reservoir. They do not all use the nutrients the same. I just try to feed what the majority want and sometimes there is a loser. I am also developing a new formula for the new 2 Part Mega Crop. I went a little crazy with the magnesium - ooops.

She is not happy - can you say salve!

 

[the123321]

Thanks.