Light burn from t5s?

[Tll7]

Hey everyone!

I’m pretty late into flower, I’m thinking I have another few weeks til chop. I’ve been struggling with what I believe is light burn for the past month or so, despite using a t5 ho light (2’x8 bulbs). Everything I have read about t5 lighting for cannabis says you can keep them super close with no consequences and you actually should because they are not as powerful as other lights.

I currently have them 5 inches from the tops and I only read about 28,000 lux with a light meter and around 650 ppfd with the korona app (I know it probably isn’t too accurate). I had no problems until midway through flower and I had to move the light higher even though it was about 3 inches from the plant in veg. At first I suspected nute burn but it only affects the top 3 or 4 leaves of each top.

Anyone have any idea why she’s burning like this? My last run didn’t have this problem

 

[thumper60]

They look waxy with lots of burned tips. what you been feeding it?

 

[oill]

Hey everyone!

I’m pretty late into flower, I’m thinking I have another few weeks til chop. I’ve been struggling with what I believe is light burn for the past month or so, despite using a t5 ho light (2’x8 bulbs). Everything I have read about t5 lighting for cannabis says you can keep them super close with no consequences and you actually should because they are not as powerful as other lights.

I currently have them 5 inches from the tops and I only read about 28,000 lux with a light meter and around 650 ppfd with the korona app (I know it probably isn’t too accurate). I had no problems until midway through flower and I had to move the light higher even though it was about 3 inches from the plant in veg. At first I suspected nute burn but it only affects the top 3 or 4 leaves of each top.

Anyone have any idea why she’s burning like this? My last run didn’t have this problemView attachment 4838705

Nitrogen toxicity from overfeeding

 

[Tll7]

They look waxy with lots of burned tips. what you been feeding it?

I started with dynagrow foliage pro and bloom at half strength. At the beginning of flower I switched to earth juice grow, bloom, catalyst, and cal mag at full strength. The company claims to be non-burning organic which Is why I did full strength. I did notice the waxyness and gave her 3.5 gallons of only water yesterday. Not enough to be a real flush but a lot more than she usually gets

 

[thumper60]

I started with dynagrow foliage pro and bloom at half strength. At the beginning of flower I switched to earth juice grow, bloom, catalyst, and cal mag at full strength. The company claims to be non-burning organic which Is why I did full strength. I did notice the waxyness and gave her 3.5 gallons of only water yesterday. Not enough to be a real flush but a lot more than she usually gets

No need to flush just use plain water for a few days i bet that waxy look will go away, Your getting close no need to dump a bunch of stuff on it now just cruse

 

[Tll7]

Nitrogen toxicity from overfeeding

from everything I have read about nitrogen toxicity, the leaves turn dark green and claw. There are definitely dark green leaves on the plant (no clawing) so there could be nitrogen toxicity, but would that cause the yellowing leaves? Or is that a separate issue?

 

[Tll7]

No need to flush just use plain water for a few days i bet that waxy look will go away, Your getting close no need to dump a bunch of stuff on it now just cruse

Damn, I’ve got a batch of no nitrogen nutes bubbling away now. I guess I’ll toss them or feed at 1/4 strength. Do you think the yellow leaves are because of excess nitrogen or a separate thing?

 

[oill]

from everything I have read about nitrogen toxicity, the leaves turn dark green and claw. There are definitely dark green leaves on the plant (no clawing) so there could be nitrogen toxicity, but would that cause the yellowing leaves? Or is that a separate issue?

It locks out all your nutes and then they go yellow.

 

[PadawanWarrior]

Hey everyone!

I’m pretty late into flower, I’m thinking I have another few weeks til chop. I’ve been struggling with what I believe is light burn for the past month or so, despite using a t5 ho light (2’x8 bulbs). Everything I have read about t5 lighting for cannabis says you can keep them super close with no consequences and you actually should because they are not as powerful as other lights.

I currently have them 5 inches from the tops and I only read about 28,000 lux with a light meter and around 650 ppfd with the korona app (I know it probably isn’t too accurate). I had no problems until midway through flower and I had to move the light higher even though it was about 3 inches from the plant in veg. At first I suspected nute burn but it only affects the top 3 or 4 leaves of each top.

Anyone have any idea why she’s burning like this? My last run didn’t have this problemView attachment 4838705

There's no way it's light burn. I had mine practically touching the whole time. I'd say it's what you're feeding or something.

 

[Eastownclan]

I have grown with t5s and 5” distance will give you a bunch of extra airy larf. It can’t be light distance. You want 2” from the tops if possible, even if they grow right into it, as long as they aren’t touching it for like a day or more, they shouldn’t get light stress.

 

[Tll7]

It locks out all your nutes and then they go yellow.

Gotcha. It’s just weird that only some of the tops are turning yellow. And the ones that are turning yellow, only half of the leaves are fading

 

[Tll7]

I have grown with t5s and 5” distance will give you a bunch of extra airy larf. It can’t be light distance. You want 2” from the tops if possible, even if they grow right into it, as long as they aren’t touching it for like a day or more, they shouldn’t get light stress.

Hmm okay I’ll lower it down a bit now and then a little bit more tomorrow

 

[oill]

Gotcha. It’s just weird that only some of the tops are turning yellow. And the ones that are turning yellow, only half of the leaves are fading

Not at all... fert burn always starts with burned tips normally at the top of the plant

 

[Tll7]

Not at all... fert burn always starts with burned tips normally at the top of the plant

Right, but isn’t it strange that only a few select tops are exhibiting the yellowing? And only the ones closest to and in the most intense place under the light?

 

[oill]

Right, but isn’t it strange that only a few select tops are exhibiting the yellowing? And only the ones closest to and in the most intense place under the light?

A t5 is like a candle mate! They are closest to the light aka the topnof the plant.... its normal.