Too much light?

Opm

Opm

Active Member
I have been chasing down this nutrient problem in late bloom when I noticed something odd.
I have one plant that is in the corner that has yellowed up on the side facing the light but still green on the other side.
IMG_20121125_104323.jpg

After some careful perusing I noticed this was similar with all the plants not directly under the light and haven't been moved in a while.

I thought it was a nitrogen problem so I got some high N bat guano and sprinkled some on top of the soil to get gradually watered in. Didn't help.
Then I was thinking maybe a sulphur problem since I use well water that may be high in calcium. So I have been watering with Epsom salts every so often. Didn't help.
Now I am thinking maybe I am bleaching the leaves with too much light.

My setup: 3 x 1k lights over 18 plants in a room roughly 5'x11'
Technoflora series nutes (complete line) PH'd to 6.3-6.4 in a soiless mix.
Soil PH is between 6.5-7
This plant is 6 weeks into flower and takes ~60 days to finish.

I should add the light is about 12" above the canopy but well ventilated and climate controlled.
 
Psychonaughtical

Psychonaughtical

Active Member
Opm said:
I have been chasing down this nutrient problem in late bloom when I noticed something odd.
I have one plant that is in the corner that has yellowed up on the side facing the light but still green on the other side.
View attachment 2422331

After some careful perusing I noticed this was similar with all the plants not directly under the light and haven't been moved in a while.

I thought it was a nitrogen problem so I got some high N bat guano and sprinkled some on top of the soil to get gradually watered in. Didn't help.
Then I was thinking maybe a sulphur problem since I use well water that may be high in calcium. So I have been watering with Epsom salts every so often. Didn't help.
Now I am thinking maybe I am bleaching the leaves with too much light.

My setup: 3 x 1k lights over 18 plants in a room roughly 5'x11'
Technoflora series nutes (complete line) PH'd to 6.3-6.4 in a soiless mix.
Soil PH is between 6.5-7
This plant is 6 weeks into flower and takes ~60 days to finish.

I should add the light is about 12" above the canopy but well ventilated and climate controlled.
Click to expand...

Definitely too close at 12 inches. Check out this chart my friend, it will give you a bit of a basis for distances and their par.


View attachment 2422338


I should add that what you're experiencing seems to be bleaching. Which effectively destroys the plants ability to perform photosynthesis in the bleached areas.
 
Opm

Opm

Active Member
It's nice to have a second opinion. Thanks.

I should clarify a bit. The glass from the hood is about 12" which would make the bulb itself about 16".

Do you go by the bottom of the hood or the actual distance to the bulb?

And why is the bottom of the plant on that side, which would be much further from the bulb, affected?
 
kenny ken 77

kenny ken 77

Well-Known Member
Bruv! Accept the burn! Don't raise your lights, less you want airy elongated kolas. Only 2 and a bit more weeks now, just learn for your next go,raise your lights a little. I had bleaching too! Raised my lights about 2 weeks into flower and the cunts stretched like fuck! 3 weeks 3 days is roughly the usual period of stretch, though raising the lights caused them to keep going, yield was good, though in my heart of hearts I so wanted them to pod up properly. Though learning with each and every grow. Good luck mate. :)By the way, I like the name OPM, opium, hmmm! ...lol!
 
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MajorCoco

MajorCoco

Well-Known Member
I think that its possible that some deficiencies show earliest wherever growth is quickest, which would be where photosynthesis is at its greatest. Just a theory though..and the effect doesn't last long before the deficiency moves on to more shaded growth...
 
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Opm

Opm

Active Member
I really need to a) have the water tested so I can properly fertilize or B) Buy a RO system. I normally use the RO that comes off my dehumidifier but during the winter the ambient air is pretty arid so I don't collect as much.

Too many unknowns at this point.
 
MajorCoco

MajorCoco

Well-Known Member
Yeah. I think you'd be able to tell if it was bleaching anyway, cos that's usually whitish rather than yellow I think. Water or pH is a more likely culprit.
 
TheOrganic

TheOrganic

Well-Known Member
Ive seen buds with light bleaching and ya they turn white as hell and have no trichs on them its a horrible site. This is def something other than light bleaching since your yellowing on one side of plant which is weird anyway. My water is hard as hell at 270ppm but I cut it in half with Ro water and use epsom salt when I brew up teas every so often. I'm thinking your lacking P with yellowing leaves like that up and down plant.
Are you watering the soil evenly. Sometimes I will water plant at bottom and leach up to take care of dry spots that I find with moisture meter that have been persistent.
 
Opm

Opm

Active Member
Just an update for those wondering.

I had my well water tested and it is actually fairly low at 249 ppms.

I contacted the nutrient manufacturer and they suggested I drop my food/water ph to 5.8-6.2. They recommend using hydro ph ranges with soiless mixes. I have been using the low side of soil ph ranges and it is still causing the lockouts. We will see if it remedies things but it makes sense.
 
M

medical/420

Active Member
I think it is too much heat on the leafs. you may think it is cool in your room, but what is the tempeture at the leaves????
 
Opm

Opm

Active Member
Using an infrared thermometer to measure, the leafs stay about 75-80. I am using C02 as well.
 
R

ricky6991

Well-Known Member
Not light bleachin.... i have 3 1kw lights over 9 plants that are cooled and are bout 14" from the glass without any problems. Like someone said, possibly watering one side of the plant more than another... wierd issue if the ph was issue then it would entire plant issue not just half.
 
Opm

Opm

Active Member
ricky6991 said:
Not light bleachin.... i have 3 1kw lights over 9 plants that are cooled and are bout 14" from the glass without any problems. Like someone said, possibly watering one side of the plant more than another... wierd issue if the ph was issue then it would entire plant issue not just half.
Click to expand...
Maybe the theory about the disorder affecting the side with a higher rate of photosynthesis quicker is accurate.
 
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