So what exactly was the problem and how was it resolved - what did you observe? The thread title does mention N deficiency and/or light burn.
Thanks.
Nitro deficiency or light burn?
- Thread starter DoubleAtotheRON
- Start date
Thanks.
DoubleAtotheRON
Well-Known Member
Wow.. this is an old thread from 2018... I think it was light burn if I recall correctly.
OP said:
But either way, I got excited when he said:
and wondered if there were more details, like was it just too 'intense' light for them at that point - not 'burn', for example, regardless of the height he had them at, etc., because also a meter was mentioned but no ppfd measurement, anyway - I got curious.
All good.
No prob.
Thanks.
DoubleAtotheRON
Well-Known Member
Yes sir!.. I recall seeing this directly under the lights, and the ones off to the side of the light were more green/less pale. So, I assumed the light was just a little too close. I think this was one of our first grows with the HLG's and I didn't have a feel for them at the time. Cheers!
Kassiopeija
Well-Known Member
its because light intensity drives photosynthesis, which, in turn, drives the local consumption of stored minerals. Thats why they brighten up. Its not from photodestruction as there the leaves would wrinkle & fall off.
Renfro
Well-Known Member
I didn't read the whole thread but just at an initial glance I would say the plants were borderline hungry, perhaps due to ph lockout or low PPM and the lights being so close was pushing the harder causing deficiency to appear, moving the lights away slowed the plants down and the feed was then "enough" for that growth rate.
I've encountered similar but instead had to dim the leds, due to height, and was surprised when dimming the leds improved the growth rate. I think feed strength was increased, also not what I thought the issue was, a little soon after and that contributed to big growth increase. This was with a new nutrient line, for the first time.
So often, I find pH the or at least an issue, too, you're right.
Kassiopeija
Well-Known Member
indeed this is the typical process when plants are lighting up but its mistaken as light bleaching... or sometimes when buds start to swell and suck minerals in - if feedings are not sufficient itll brighten up, top or bottom...
outside the summer sun can deliver 12-14h of brutal +1700ppfd when ambient temps are high (+30°C) + the suns IR is further heating up leaves + outsides theres low CO2 + UV, and still... no bleaching!
Im listing these parameters bc chlorophyllic photodestruction (or complete plant "lightdeath") is not caused by the photons themselves (even if the heat is increasingly mounting) but due to toxic metabolites as a result of reaching the light saturation point (CO2 hard capping)
Renfro
Well-Known Member
The bottom up progression definitely indicates that it's not the light intensity directly damaging the plant, it's a nutrient issue. The fact reducing light intensity caused the plants to look better only indicates the feed was then adequate. If I am not mistaken, since this thread the OP started checking the pH of the root zone and this allowed him to pinpoint his uptake problems in his subsequent runs. I will let @DoubleAtotheRON speak for that. To think of it he may have increased his PPM as well, I can't remember for sure.
He said "top to bottom" though...
That doesn't mean the lights to intense thats a deficiency. More light needs more nutes. If you lower the light levels they need less nutes so you would see better growth with less light if you aren't feeding enough. Like if you have an even 800 ppfd spread vs 1000ppfd the nutrient needs are very different
DoubleAtotheRON
Well-Known Member
I did increase the feed as I raised the lights, this seemed to balance it out if I remember correctly. Agree that the more intense light was starving them. I ran across this on the last run again, and did the same thing, and it sorted itself out. Now with the new CO2, I find I can run 1200 ppm and blast them with light and 86 degrees with no problems.
mateobeast88
Member
They look way to high! I keep my plants in a sweet spot to where they are literally PRAYING to the sky, meaning my leaves look firm reaching upwards.
DoubleAtotheRON
Well-Known Member
Yeah.. it worked out tho. I was getting used to the new HLG's in 2018. You can see the last grow in my signature.
mateobeast88
Member
Indeed they did VERY SEXY, how tall were your plants before you switched over to flower and typically how tall were they in the end?
DoubleAtotheRON
Well-Known Member
I'd say about 2 1/2 ft on the flip. I top twice early on. Once they get close to the net, I'll flip em and tie back, supercrop,and weave them through the net to spread them out as much as possible as they stretch. This is how I can get a better even field. I've grown these strains 3 times cloned, so I know how they're going to stretch and behave. Kicking out 2 strains and introducing 2 new ones for the Fall run of 78 plants. I just dont like Kosher Sorbet.. and I fucking hate Cindy99. In the end, I get a good stretch of good stacking Dosi Whoa! at ~ 18 inches above the net, Orange Kush stays pretty low on the net at ~6-8 inches above. Same with Early Lemon Berry (high yielder)
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Gond00s
Well-Known Member
why didn't u like the cindy? is it because it can foxtail pretty hard because i noticed that with mine.
DoubleAtotheRON
Well-Known Member
She's a short grower, and really bushy. Takes alot of maintenance, and really is not that great of a producer. Buds are dense, but not alot of them. This is the one and only strain we noticed bud rot due to the very dense but sparse bud sites.