Blackstar 500w LED light-bleaching?

[fuzzymuffin]

Hi. I'm currently using this light in my grow (3 Nirvana NL in hempies.) I'm about a week into veg and have been having what I thought was N deficiency. As I was examining my plants I noticed that the plants farthest from the light were looking much better (darker foliage w/less streaking) than the ones closest to the fixture but the ones closer to the light have more uniform growth with somewhat tighter spacing but excellent leaf shape. I raised the light about six inches yesterday and today was gifted with seeing that the plants closest to the light have gained some color while the ones farthest away have begun to stand properly with no noticeable ill effects from the light being moved. I had the light at about 15 inches and raised it to 20-21 inches. I'm thinking the light was bleaching the plants (it's quite intense) closest to it. Anybody else experience something like this with this light or something similar? Any advice you might have for me? Thanks.

 

[rives]

I use a Lumigrow ES330 and have no experience with a Blackstar, but I think that you nailed it. The higher power LED's can bleach the hell out plants, particularly young ones. Several of us have noticed that the LED's seem to make the need for additional magnesium more pronounced, so you might keep an eye out for that, too.

 

[fuzzymuffin]

Thanks. That's reassuring for me. I'll continue to keep an eye on things but do you think I might want to move it even farther away? I guess time will tell. I'm thinking the nutes are OK as the plants farthest from the light are pretty good and they are all receiving the same food.

Now that I've said that, I'll probably be eating my words before long...

 

[GP73LPC]

just out of curiosity, how much do you think you will yield with the Blackstar...?

has you grown with it before?

 

[GP73LPC]

oops, duplicate post...


slow ass, flaky internet sucks...

 

[alkalien]

I have noticed a, to me, new form of bleaching from LEDs too close to the plants:

I get that white head with every strain at a distance of less than 10cm / 4". But that's from red LEDs. Trying the same with XM-Ls will wilt the leafes. Using lenses your distance will pretty much do the same, the plants just stop growing. I actually hang the lights a little bit higher for early flower to increase stretch

 

[rives]

Yep! This was at about 12"-14" with my ES330.

 

[fuzzymuffin]

just out of curiosity, how much do you think you will yield with the Blackstar...?

has you grown with it before?

I have no idea. It's my first time using it so I'm kinda flying blind.

I'm also starting to think it might be a little too much light for my tent. I'm using a 2x4 hydrohut. When I got the light, I had been planning to step up to a bigger tent as well but decided I didn't really need the bigger space due to how little I grow. The plants are looking nicer now and I raised the light another 3-4 inches (I'm just going by eye) as the plants are growing like... well... weeds. Probably going to cull one out in the next week if it doesn't buck up, though.

 

[fuzzymuffin]

I have noticed a, to me, new form of bleaching from LEDs too close to the plants:

I get that white head with every strain at a distance of less than 10cm / 4". But that's from red LEDs. Trying the same with XM-Ls will wilt the leafes. Using lenses your distance will pretty much do the same, the plants just stop growing. I actually hang the lights a little bit higher for early flower to increase stretch

Wow, that's crazy looking! Kinda weird how the rest of the bud looks healthy while the very top is albino white. Do you experience this on all the buds or just the main cola?

 

[GP73LPC]

I have no idea. It's my first time using it so I'm kinda flying blind.

well good luck...

i'd like to know how it turns out for you.

 

[fuzzymuffin]

well good luck...

i'd like to know how it turns out for you.

Thanks. It's been interesting so far. The light bleaching is a first for me and kinda freaked me out a little. Easy fix, though. One huge difference I've seen so far with this light v. CFL is how tight the node spacing is on the plants. I'm getting new nodes about 1/2"-3/4" apart. With CFL, I get 1"+ spacing. It's kinda got me wondering if the higher growth will shade out the lower leaves. The light is pretty intense, though. Perhaps it's enough to penetrate through the canopy. I'm still in early veg, though, so only time will tell.

 

[GP73LPC]

LEDS do tend to produce shorter plants with tighter internodes...

 

[fuzzymuffin]

LEDS do tend to produce shorter plants with tighter internodes...

That's what I'd heard. Seeing it first-hand has been a bit of a trip for me, though.

 

[fukndenny]

What does this mean? :|

 

[rives]

Perhaps it's enough to penetrate through the canopy. I'm still in early veg, though, so only time will tell.

Penetration hasn't been an issue for me with the Lumigrow. I just harvested my latest batch, and found a bud that was clear in the back of the tent, under the screen, and completely shaded by the growth above it. It wasn't quite the same size as the ones above, but damn close.

 

[alkalien]

Wow, that's crazy looking! Kinda weird how the rest of the bud looks healthy while the very top is albino white. Do you experience this on all the buds or just the main cola?

This happened in a PC Case microgrow and only one bud was that close to the lamp. But that wasn't the first run for this cabinet and I could find a distance at which buds start to behave like that. The strain does not matter

 

[fuzzymuffin]

This happened in a PC Case microgrow and only one bud was that close to the lamp. But that wasn't the first run for this cabinet and I could find a distance at which buds start to behave like that. The strain does not matter

Have you noticed any difference in trich formation/quality in the white section? I see a lot of nice pistils in the effected area but I'm wondering if the light didn't, sort of, top off the bud.

 

[fuzzymuffin]

What does this mean? :|

Do you mean "what is light bleaching?" I'm not an expert by any means, but from what I understand it's caused by an overabundance of light that actually causes the plant to produce less chlorophyll and xanthophyll in it's growing leaves which causes the foliage to take on a pale green, almost yellow, appearance. If left unchecked and not corrected for, it can kill the plant or produce stunted growth. Not only that, it can hide nutrient deficiencies in the plant so that by the time you realize there's a problem, it's too late to correct.

Not a thing to be left unattended to.