Is My LED Bleaching/Killing My Plants??? Pictures

CaptainAhab

CaptainAhab

Member
I have a Blackstar 240 Watt LED specific for veg/clones seen here: http://www.blackstarled.com/24blclandve.html and it's covering a area of approximately 2 feet x 2 feet at a distance of less than 1 foot from the top of the canopy. My plants have yellowing, reddish, sometimes curling leaves as seen in the pictures, here:
photo(6).jpg

photo(7).jpg

The plants are in a tent that has constant temperatures in the mid 70's, and the temperature at the top of the canopy does not get over 80. The plants are potted in Fox Farms Ocean Forest soil, and no ammendments, no fertilizers, no NOTHING has been added to the soil.

This looks like some sort of nutrient burn, or bleaching, or something. All I know is that all my plants have this same yellowing/reddening/curling going on, and it's disturbing me.

What are your opinions on this?

Thanks
 
Alex281

Alex281

Well-Known Member
how much you been watering/phing/nutrient amounts? looks like something along those lines.
 
CaptainAhab

CaptainAhab

Member
Alex281 said:
how much you been watering/phing/nutrient amounts? looks like something along those lines.
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I don't water that often. The soil has been staying relatively moist for days at a time with no watering. I haven't ph'ed the soil, because I figured that I wouldn't need to, just using Fox Farms Ocean Forest with no additives. I thought that stuff was pre-pH balanced and safe to use as is. I have a hydroponics pH test kit I can test run off with.
 
WattSaver

WattSaver

Well-Known Member
CaptainAhab said:
I don't water that often. The soil has been staying relatively moist for days at a time with no watering. I haven't ph'ed the soil, because I figured that I wouldn't need to, just using Fox Farms Ocean Forest with no additives. I thought that stuff was pre-pH balanced and safe to use as is. I have a hydroponics pH test kit I can test run off with.
Click to expand...
What Alex281 wanted to know is what the ph of the water you are using to water with. 6.5 to 7.0 will work fine. FFOF is great soil, but if you are watering with water in the 5.5 and lower or 7.8 or higher, it will ruin the soil and the plant. You should be feeding these plants by now, they look old enough for food.

Now the scorching. Yes a 3w unit at 12" above canopy can & will bleach and kill foliage. With young plants I wouldn't let it get within 24".... 36" would probably be best if you have an enclosed space with reflective walls.

I have one of the first 3w units it is 6 band with a combo of 1w & 3w diodes. 2/3's are 3w. Ran it for 2 yrs. My 1st grow with it, I had read how close you had to keep LED's (these were 1w or less units) I set the light at 6" above canopy, it completely stunted the plants, they had no stretch going into flower, and didn't grow more than 3 to 4" during flower. In the end I kept the light at least 16" and most of the time 20" to 24" above the canopy.
I played around with a 180w fixture with 6w diodes once (3 days) all I could think of was fire hazard. It put off more heat than a 250w hps.
 
CaptainAhab

CaptainAhab

Member
WattSaver said:
What Alex281 wanted to know is what the ph of the water you are using to water with. 6.5 to 7.0 will work fine. FFOF is great soil, but if you are watering with water in the 5.5 and lower or 7.8 or higher, it will ruin the soil and the plant. You should be feeding these plants by now, they look old enough for food.

Now the scorching. Yes a 3w unit at 12" above canopy can & will bleach and kill foliage. With young plants I wouldn't let it get within 24".... 36" would probably be best if you have an enclosed space with reflective walls.

I have one of the first 3w units it is 6 band with a combo of 1w & 3w diodes. 2/3's are 3w. Ran it for 2 yrs. My 1st grow with it, I had read how close you had to keep LED's (these were 1w or less units) I set the light at 6" above canopy, it completely stunted the plants, they had no stretch going into flower, and didn't grow more than 3 to 4" during flower. In the end I kept the light at least 16" and most of the time 20" to 24" above the canopy.
I played around with a 180w fixture with 6w diodes once (3 days) all I could think of was fire hazard. It put off more heat than a 250w hps.
Click to expand...
Thanks for the reply. Given what the manufacturer's website says in the link above, http://www.blackstarled.com/24blclandve.html , it says that light has an " Optimal Distance To Canopy: 10"-14" ."

I wouldn't have guessed that it would be the lights distance, but that's why I started the thread, since it seemed very suspect. I will post update photos as they come in.
 
B

Buccanier

Member
Hi,
I am new here and having great fun with my first very small attic/closet grow. I started with 5 feminised kush seeds, a Heath Robinson box and a 200W CFL. Seemed to go ok 4 seeds germinated and grew quite nicely until disaster struck and the CFL blew leaving me with no spare. I managed to keep the plants in the conservatory for a day or so and then decided that as CFLs were obviously unreliable that I would go LED and boughta 90W UFO. I put this at around 8" above the plants and congratulated myself on my economy and good sense. 2 days later the top leaves had turned yellow. I foolishly suspected that it was insufficient light and moved the UFO to within 4" and totally frazzled them. So by this time a replacement CFL had arrived and the UFO was ditched. In fairness my temps were high 90 ish without a fan but I didn't think that they would survive. I installed a small fan and an air vent reducing the temp to around 75-80 and they have all pulled through. I intend to go 12/12 within a day or so as I am short of space and only need a little to keep the wife and I chilled occasionally. I am however, terrified of usiing the LED I would have gone CFL + LED for flowering but will stick to 2 CFLs now. After all that rambling my point is that everyone is blaming various nute deficiencies for what is simply LED burn. There was nothing wrong with my John Innes No 2 compost it was fresh and ideal for seedlings. I think that perhaps if you switch from CFL to LED during a grow that the plant can't handle the new light spectrum - shall try an LED only grow next time and watch my temps. See attached pics of the best recovery since Lazerus. Cheers all any advice gratefully received.Frazzled_1600x1064.jpgrecoverd_1600x1064.jpg
 
CaptainAhab

CaptainAhab

Member
Buccanier said:
Hi,
I am new here and having great fun with my first very small attic/closet grow. I started with 5 feminised kush seeds, a Heath Robinson box and a 200W CFL. Seemed to go ok 4 seeds germinated and grew quite nicely until disaster struck and the CFL blew leaving me with no spare. I managed to keep the plants in the conservatory for a day or so and then decided that as CFLs were obviously unreliable that I would go LED and boughta 90W UFO. I put this at around 8" above the plants and congratulated myself on my economy and good sense. 2 days later the top leaves had turned yellow. I foolishly suspected that it was insufficient light and moved the UFO to within 4" and totally frazzled them. So by this time a replacement CFL had arrived and the UFO was ditched. In fairness my temps were high 90 ish without a fan but I didn't think that they would survive. I installed a small fan and an air vent reducing the temp to around 75-80 and they have all pulled through. I intend to go 12/12 within a day or so as I am short of space and only need a little to keep the wife and I chilled occasionally. I am however, terrified of usiing the LED I would have gone CFL + LED for flowering but will stick to 2 CFLs now. After all that rambling my point is that everyone is blaming various nute deficiencies for what is simply LED burn. There was nothing wrong with my John Innes No 2 compost it was fresh and ideal for seedlings. I think that perhaps if you switch from CFL to LED during a grow that the plant can't handle the new light spectrum - shall try an LED only grow next time and watch my temps. See attached pics of the best recovery since Lazerus. Cheers all any advice gratefully received.View attachment 2117559View attachment 2117560
Click to expand...
Yeah, I narrowed my plant problems down to LED burn. Since I created this thread, I've done more research, and seen the same thing over and over again from people suspecting nutrient deficiencies, overfeeding, heat, whatever, in threads like this: https://www.rollitup.org/marijuana-plant-problems/515575-bleached-leaf-blackstar-led-flower.html

Your pictures look exactly like LED burn, to me. You need to solve your heat problem, too.
 
B

Buccanier

Member
Glad you agree -the forums have been a great help in setting up but there is an amazing load of crap preached. These plants normally live in a hostile environment where temperatures, rainfall and soil will vary incredibly. Keeping them lit, watered, fed a little and making sure that they are not in an oven should be sufficient for their needs.
What do you reckon would be a safe height for LEDs from the plants? I decided that it was lack of ventilation and not the LED so I installed a fan lowered the temps to 75-80 and put the UFO at 12" - and still got bleaching!!! and yet I have seen pics of plants almost touching LEDs in perfect health - I am guessing if you start with LEDs it may allow the plant to become accustomed to the wavelength Anyway Cheers for your good advice.
 
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