HLG 600's and leaf burn

Has anyone else had serious trouble with spectrum burn on leaves with the HLG or quantum board LEDS?

It's crazy how far away I have to keep my lights or else my leaves burn.

They were pretty burned in early veg, so I turned the lights all the way down and raised them to like 3 feet. Boom plants were loving life again they vegged great and filled out the canopy nicely. Even when I flipped to flower I left the lights raised all way up and dialed all the way down.

Now here's the thing, I caved and bought that apogee ppfd meter that can pick up the far red spectrum, damn thing was like 700$.

Well none of my reading make any sense for what my plants are communicating with me. I was at about 200 ppfd all throughout veg, if I turned them up any more my leaves would instantly begin to burn.

So I just decided to ignore the meters readings and listen to the plants, so I left the lights turned all the way down and as far away as possible.

Now after day 21 of flower, my buds were looking small, like real small. So I stupidly busted out the apogee meter and turned my lights up to about 800 ppfd at the canopy. Well within two days of turning up the lights, my leaves FRIED. So I turned my lights back down yet again, and praying they will recover.

So I've had many successful runs with these LEDs in tents. But then I built a room that is 11'x11' and put my four lights in it. This is my second run with all four hlgs running, and the EXACT same thing that happened last time. Everyone was very quick to tell me it was my PH, VPD, overeatering. Well it's not, it's these high intensity LEDS. I've grown weed under the sun, and under nanolux DE many times successfully. And even with these LEDs successfully when each one was in its own 4x4 tent. But for some reason having them in an array on the ceiling makes my plants burn to a crisp at low ppfd ranges.

Just wondering any one else notice/ experience this?

Btw I'm using nectar 4 the gods full nutrient line in soil. I do feed, feed, compost tea, repeat.

First picture is plants after I moved the lights away and dialed all the way down. I even covered my mylar walls with tapestries because it seemed the reflection of the mylar was contributing to the burn.


So the second picture is day 23 of flower, two days after I decided to turn my lights up to 800 ppfd and remove the tapestries exposing the reflective mylar again.

I do slurry tests. I check my runoff when I get it. I keep my temp and humidity dialed. My plants get plenty of calcium. Also after turning the lights up on the last run and the same thing happening, I took one plant out and put it under a viodrspectra blurple led, the new growth began to thrive and no burning occured at all. Likewise I brought a veg plant that was super healthy into my hog quantum board room and again within two days the leaves crisped up.

So I'm just not understanding why the ppfd reading from my apogee meter it's consistent with what everyone says.

There's something wierd about these high intensity r spec LEDs and I want to get to the bottom of it! Chime in of you've experienced what I'm talking about. If you've never actually tried growing with high intensity LEDS I don't need any input, because everyone who hasn't grown with them tells me it's a pH lockout. It's 100% not s pH issue. I also have the Hanna soil pen , I add slf-100 and compost teas, my rootzone is everything s plant could ask for. But if I turn my lights up to what is considered a normal range they fry.

lights at 200 ppfd and reflective walls covered. Probably day 12 of flower.

day 23 of flower. Exactly TWO days after turning my lights up to 800 ppfd.

I figured since they were done stretching and they're in full bloom they could handle it but they are pretty much dying. Obviously damaged leaves will never recover. I am around 300 ppfd now hoping they will heal and the green will come back. Just so wierd I never had these issues until I hung multiple quantum boards in an array. I used to run them at full strength 20" from the canopy in my 4x4 tents. I am stumped and frustrated lol

The 650 Diabo is a strong light with a hot spot. I have a room but no height. Six feet. It smoked my plants. In my opinion the square design puts the quantum boards too close. But that violated their recommendations anyway.

I got an HLG 650 R-Spec. It is shaped like two capital Es back to back. They came out with the R-Spec a month after I bought the Diablo. I wasn't too happy. I'm using the Diablo as a veg light, turned way down. It's flowering an auto as well.

I feel your pain. I'm not sure what your problem is. I got a par meter too. That light made me do it.

Just curious, what was your RH and temps like? A lot of times the people running high ppfd are chasing vpd, running co2, basically dialing in the rest of the environment pretty tight. I've noticed something similar with my light, needing way more distance than I expect based off of par maps and readings, but I keep my RH at 50% during flower.

I use HLG and this happened to me once because I didn't let the ladies acclimate to the increased light and temps. Had to increase the light slowly, like over a week or more. Also the increased heat was drying everything out much quicker than I thought it would.

if you replace that net with a denser metalmesh you could train/scrog the plants in (next time) to keep them lower.
the light from the LED spreads in a 120° (?) angle so, unlike a ceramic burner, has less stray beams to the side and you want to allow some distance so that the cone of light creates his footprint in arrangement with your canopy-size.
IIRC many Bugbee-meters cut of at 692nm, so some PAR + FR may be missing in the reading...

Starseed.extracts said:

Has anyone else had serious trouble with spectrum burn on leaves with the HLG or quantum board LEDS?

It's crazy how far away I have to keep my lights or else my leaves burn.

They were pretty burned in early veg, so I turned the lights all the way down and raised them to like 3 feet. Boom plants were loving life again they vegged great and filled out the canopy nicely. Even when I flipped to flower I left the lights raised all way up and dialed all the way down.

Now here's the thing, I caved and bought that apogee ppfd meter that can pick up the far red spectrum, damn thing was like 700$.

Well none of my reading make any sense for what my plants are communicating with me. I was at about 200 ppfd all throughout veg, if I turned them up any more my leaves would instantly begin to burn.

So I just decided to ignore the meters readings and listen to the plants, so I left the lights turned all the way down and as far away as possible.

Now after day 21 of flower, my buds were looking small, like real small. So I stupidly busted out the apogee meter and turned my lights up to about 800 ppfd at the canopy. Well within two days of turning up the lights, my leaves FRIED. So I turned my lights back down yet again, and praying they will recover.

So I've had many successful runs with these LEDs in tents. But then I built a room that is 11'x11' and put my four lights in it. This is my second run with all four hlgs running, and the EXACT same thing that happened last time. Everyone was very quick to tell me it was my PH, VPD, overeatering. Well it's not, it's these high intensity LEDS. I've grown weed under the sun, and under nanolux DE many times successfully. And even with these LEDs successfully when each one was in its own 4x4 tent. But for some reason having them in an array on the ceiling makes my plants burn to a crisp at low ppfd ranges.

Just wondering any one else notice/ experience this?

Btw I'm using nectar 4 the gods full nutrient line in soil. I do feed, feed, compost tea, repeat.

First picture is plants after I moved the lights away and dialed all the way down. I even covered my mylar walls with tapestries because it seemed the reflection of the mylar was contributing to the burn.


So the second picture is day 23 of flower, two days after I decided to turn my lights up to 800 ppfd and remove the tapestries exposing the reflective mylar again.

I do slurry tests. I check my runoff when I get it. I keep my temp and humidity dialed. My plants get plenty of calcium. Also after turning the lights up on the last run and the same thing happening, I took one plant out and put it under a viodrspectra blurple led, the new growth began to thrive and no burning occured at all. Likewise I brought a veg plant that was super healthy into my hog quantum board room and again within two days the leaves crisped up.

So I'm just not understanding why the ppfd reading from my apogee meter it's consistent with what everyone says.

There's something wierd about these high intensity r spec LEDs and I want to get to the bottom of it! Chime in of you've experienced what I'm talking about. If you've never actually tried growing with high intensity LEDS I don't need any input, because everyone who hasn't grown with them tells me it's a pH lockout. It's 100% not s pH issue. I also have the Hanna soil pen , I add slf-100 and compost teas, my rootzone is everything s plant could ask for. But if I turn my lights up to what is considered a normal range they fry.

Click to expand...

Wow,that is odd. I too run rspec550s..not a 600 or650..which is too strong for house growing,need lots of height.
I did experience this, but raising light,and turning down did it,and ramped up over a few weeks in veg..flower full. Once plants were used to it,smooth sailing...but not all genetics act the same under these..some are more prone to too much,bleaching..but I can't recall if you have the stronger version of what I'm using..but if so.thats probably it,if not..hmm..I'd call hlg,they are extremely helpful..

OP: whats your temps like? The higher intensity the higher temps you need.

Never tried that nutrient line but i think its organic? I havent seen much people have great luck with high intensity leds abd organic.

You cannot just turn the light up to 4x intense over night and expect your plants to like it, you need to slowly slowly push there. Led plants really have to be babied a lot but once they get there you can really turn t up.

Thanks for the feedback everyone. So in veg I run my temps around 80°F with like 70 rh, they seem to like it almost tropical in there during veg, in flower I've got it dialed back to 77°F and 60 rh.
My thinking was these figures would help transpiration if the leaves were burning from dryness. But I'm still stumped on that it's not dryness or heat stress, it's certainly spectrum intensity burn.

A few of you made a great point to turn the lights up more slowly.

See my plants were so burned in early veg, that after I backed the lights all the way off and turned them down to 50% , they recovered very quickly, and were lush and green and explosive growth (during this time my apogee par meter was reading about 150-200, which is hilarious because that's what's recommended for seedlings and these are 4 foot tall plants at this point. So anyway I thought I might even flower them at that light height and half intensity. It wasn't until I saw how small my buds were at day 21 that I busted out the apogee meter and turned them up from around 200 to 800. (,Which online some people even say gof to 1000-1200 ppfd, my plants would literally turn into crispy potatoes chips if I did that lol.

Your right I should have transitioned the light intensity more slowly, maybe over a few weeks.

Still crazy to me though cause when I ran these lights in 4x4 tents I ran em at full power in flower at like 20". , I could go from half power to full power in one day and they would just pray suuuper hard, but never burned. I've tried contacting hlg twice now through email I left my number and haven't been able to anyone.

absolute, turn the lights up more slowly.
its strange that it works in tents for you and not open space, should be the oposite as the light is far better trapped and reflected in a tent.
dont think its your fertilizer if youre otherwise fine with your mix.
200ppfd is really too low to flower, while can be very ok for veg.
i try to get my plants taking at least 300ppfd in veg before i go 12/12 within the first 2 weeks i go to at least 600ppfd, 700-800 is some quite safe target.

cobshopgrow said:

absolute, turn the lights up more slowly.
its strange that it works in tents for you and not open space, should be the oposite as the light is far better trapped and reflected in a tent.
dont think its your fertilizer if youre otherwise fine with your mix.
200ppfd is really too low to flower, while can be very ok for veg.
i try to get my plants taking at least 300ppfd in veg before i go 12/12 within the first 2 weeks i go to at least 600ppfd, 700-800 is some quite safe target.

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Okay gotchya, thanks for the input, I'll try a super gradual dial upwards next run and see if I can get the plants to acclimate. And yes it's so strange how different it is than when I ran then alone in isolated tents. It must be something about the crossover light. I looked in the manuel and hlg specs the flowering footprint at 4.5'x4.5'.
But not knowing that built 4x4 footprints, and centered each light accordingly.

So another thing I did that helped a ton after the initial veg burning was move my lights further apart. Now they do each take up about 4.5x 4.5 space. (yet I still fryed my girls by turning the power up

I've come to the conclusion that my main issue is having 7 foot ceilings and an 11x11 room. Little did I know that an array of quantum boards creates a spectrum that is too intense for those room dimensions.

I lost my entire last crop because I still couldn't imagine the lights were the issue. They were 20" away(but at full power). I had a hunch many times it was the lights, but a bunch of other growers and people online who have never used hlg or intense spectrum LEDs in an array all told me it's gotta be pH/nute lockout, there's no way it's the lights. Hey the ONLY thing that ever helped my plants was backing off the light further and further, to the point where they were attached to angle iron my carabeanernclips. They are on pullys again now because having them that close makes me nervous of possible fire safety. HLG says the lights should be 14 inches from the ceiling but I'm a small basmnet grower I don't have that kind of space .

Anyway I know for s fact it's the lights for a million reasons. During my last cycle it was still summer here in Michigan and I had a bunch of plants in pots on my deck in the backyard. I was feeding them identical nutrients and water to my hlg room. The HLG room fried while I got nearly a pound each off my outdoor girls, and not a single brown leaf the entire season they looked healthy as can be.

Rurumo said:

Just curious, what was your RH and temps like? A lot of times the people running high ppfd are chasing vpd, running co2, basically dialing in the rest of the environment pretty tight. I've noticed something similar with my light, needing way more distance than I expect based off of par maps and readings, but I keep my RH at 50% during flower.

Click to expand...

I have a similar power lights to OP (730w 301h's or 301b's depending on which one) and I would definitely agree with this, when I first went from hps to led I got tons of burn even with the lights at way lower than the plants should have been able to take and much of it went away when I started really trying to dial in my Rh and temps I never was able to run at 100% outside of flower without co2 either and even in flower the very tops would get roasted a little bit until I started supplementing co2.

I use an autopilot CO2 controller connected to a tank that keeps the ppms of the sealed room around 1200. (700 in veg) maybe I should try turning it up to like 1500 or 1600,?

Its only my 2nd grow so I don't have much data. I'll post a picture of my current setup- here's the first week of flower with the HLG 600rspec set to 50% on the dimmer (300w out the wall- tested). The lights are 28-30 inches above the canopy. Here are a couple pics from tonight. Will provide more as needed.

Grow thread here: https://www.rollitup.org/t/2nd-grow-3-feminized-slippery-susan-seeds-in-happy-frog-soil.1067862/

I start seedlings under a Gavita 1700e at full blast, and 24 inches away, and have never had a problem. My temps are 80f-82f, and 55%-70% humidity. I have tremendous Fresh airflow, use no CO2. I dont know what the umol are at that distance, but I assume very high.

I also start seedlings under a 1000W Hortilux HPS at 24in, and never get any burn. I grow in an open room, and no tent. I also assume the umol are pretty high with the HID I use both the Gavita, and Hortliux to cover 4 x 4 areas, at the same height. I know the Gavita is rated at 1700umol, and the 1000w Hortilux is 1600umol. I think a 650R is rated at 1781??
But if you use a Lumens to PPF calculator the Hortilux is rated at 1881umol, so I dont know which to believe. I know the DE Gavita is 166,000lumens, and using the calculator its 2153umol, which is spot on to Phillips rating for a 1150w DE HPS
Ive also started seedlings under the DE Gavitas at full blast, and 36-40inches, with no problems. I attribute no burning because of huge FRESH airflow

I flower with both a Hortilux 1000w HPS, and DE Gavitas. I run the Hortilux at 20-24 inches, and the Gavita 36-40in. The DE bulbs will fry them any closer than 36 inches.

My buddy ran the 650R in a 4 x 4 tent, at 50% and fried his plants. was also 3 feet away. Only thing I can see different is lack of Fresh airflow.

The sun at the equator can exceed 2000umol, but of course thats at its highest, and is not constant.
I use Promix BX as my medium, and Hydro Gardens 4-20-38-15.5-0-0 ( Calcium Nitrate ), and Epsom salts. I dont use calmag I feed my seedlings as soon as the pop at every watering at 5%- 10% of max dosage. I never exceed 30% of maximum recommend dosage.

Rurumo said:

Just curious, what was your RH and temps like? A lot of times the people running high ppfd are chasing vpd, running co2, basically dialing in the rest of the environment pretty tight. I've noticed something similar with my light, needing way more distance than I expect based off of par maps and readings, but I keep my RH at 50% during flower.

Click to expand...

Humidity at 50-55 and temps at 78-81

btw. your leaves are looking like theyre lacking some P, may get a bucket bat guano.

jimihendrix1 said:

I start seedlings under a Gavita 1700e at full blast, and 24 inches away, and have never had a problem. My temps are 80f-82f, and 55%-70% humidity. I have tremendous Fresh airflow, use no CO2. I dont know what the umol are at that distance, but I assume very high.

I also start seedlings under a 1000W Hortilux HPS at 24in, and never get any burn. I grow in an open room, and no tent. I also assume the umol are pretty high with the HID I use both the Gavita, and Hortliux to cover 4 x 4 areas, at the same height. I know the Gavita is rated at 1700umol, and the 1000w Hortilux is 1600umol. I think a 650R is rated at 1781??
But if you use a Lumens to PPF calculator the Hortilux is rated at 1881umol, so I dont know which to believe. I know the DE Gavita is 166,000lumens, and using the calculator its 2153umol, which is spot on to Phillips rating for a 1150w DE HPS
Ive also started seedlings under the DE Gavitas at full blast, and 36-40inches, with no problems. I attribute no burning because of huge FRESH airflow

I flower with both a Hortilux 1000w HPS, and DE Gavitas. I run the Hortilux at 20-24 inches, and the Gavita 36-40in. The DE bulbs will fry them any closer than 36 inches.

My buddy ran the 650R in a 4 x 4 tent, at 50% and fried his plants. was also 3 feet away. Only thing I can see different is lack of Fresh airflow.

The sun at the equator can exceed 2000umol, but of course thats at its highest, and is not constant.
I use Promix BX as my medium, and Hydro Gardens 4-20-38-15.5-0-0 ( Calcium Nitrate ), and Epsom salts. I dont use calmag I feed my seedlings as soon as the pop at every watering at 5%- 10% of max dosage. I never exceed 30% of maximum recommend dosage.

Click to expand...

Thanks for the input. I do run a run a tightly sealed room , there is no fresh air, just CO2 from the tank. This is something I will investigate.

cobshopgrow said:

btw. your leaves are looking like theyre lacking some P, may get a bucket bat guano.

Click to expand...

I feed them bat guano tea, I don't think the roof zone could be any more rich with nutrients and living microbes