Can Anyone Confirm Whether This Is Light Burn?

Looks overwatered a little maybe, i dont see any light burn. Do you have a fan blowing directly on it? It would be easier to tell if you had a pic innregular light.

3N1GM4 said:

Looks overwatered a little maybe, i dont see any light burn. Do you have a fan blowing directly on it?

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Yes but it's a very little fan that i run 5 hours a day. Slight breeze.

I would put the fan blowing just over the top of the plant and leave it on the whole time the light is on. It may be a heat issue if you only leave the fan on a few hours. The temp 9 inches from your light is most likely higher in spots. Hold your hand under the light near the top of the plant, if it is really warm on your hand it is too hot. Either move your light further away or use a bigger fan.

3N1GM4 said:

I would put the fan blowing just over the top of the plant and leave it on the whole time the light is on. It may be a heat issue if you only leave the fan on a few hours. The temp 9 inches from your light is most likely higher in spots. Hold your hand under the light near the top of the plant, if it is really warm on your hand it is too hot. Either move your light further away or use a bigger fan.

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Yeah, i did the hand test and its just warm, no pain, nothing. I don't think it's the heat

Your body is 98.6 F if it feels warm then it is probably above 90F since your skin is cooler. If in doubt use an infra red thermometer or place the thermometer right near the top of your plant and read it 20 minutes later.

Looks like a potassium deficiency

Sorry i forgot to convert C to F as I am in the sates. 29C is a bit high, 25C is ideal
29C is getting close to killing temp

High temps will cause the edges of the fan leaves to curl like that, i cant see any def with that light

3N1GM4 said:

Sorry i forgot to convert C to F as I am in the sates. 29C is a bit high, 25C is ideal
29C is getting close to killing temp

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I'll get her further right away. How further wouldnt make my lights wasted?

Another 5 cm would probably be enough, or it may be enough to just leave the fan blowing over top them when the light is on since it is a smaller light.

I'm going to be an ass and mention that if you were really solicitous of a wide array of opinions you would provide the appropriate temperature and distance conversions so that us stupid americans know wtf…

However, in retrospect, that's totally moot because neither seems to be a factor. Ph issue compounded by overwatering expressing itself as K deficiency.

rascali said:

I'm going to be an ass and mention that if you were really solicitous of a wide array of opinions you would provide the appropriate temperature and distance conversions so that us stupid americans know wtf…

However, in retrospect, that's totally moot because neither seems to be a factor. Ph issue compounded by overwatering expressing itself as K deficiency.

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Sorry my bad, should've provided with the US versions. Thanks for your input. Quick question, i feed her 7.0 PH distilled water, does adding nutrients to the water raises/lowers the PH? Soil is 6.2 PH

You are supposed to ph the water after adding nutes

rascali said:

I'm going to be an ass and mention that if you were really solicitous of a wide array of opinions you would provide the appropriate temperature and distance conversions so that us stupid americans know wtf…

However, in retrospect, that's totally moot because neither seems to be a factor. Ph issue compounded by overwatering expressing itself as K deficiency.

Click to expand...

So you are saying the temps being 70 to 85 F in the room, that they couldnt be above 85 9 inches from the light causing the edges of the leaves to curl?

I also can not see how you see a def in that pic, you need a pic under flourescent or a flash to see the real colors.

I think its partial heat stress/light burn for sure. I just finished going through this in a 10x20 room with a 1k on a track, 3ft above the entire canopy (veg). Also made the mistake of having a fan blowing on them all too, instead of moving air around. It also had to do with not having high enough humidity in there, so i framed in a 20" box fan to bring in some nice humid air. Need to make sure you've got new air supply, and aren't only moving stale air around in the same area. Everything is starting to clear up, added a 16" hurricane fan, oscilatting l/r right above them, and a 8" booster blowing out. Humdity temps are nearer to 70% now from the outside air, and im seeing a major difference. I would be careful about watering the really weak onces that are already pretty wed in my case a few sour OGS. Make sure you let the weak ones dry out nice and remember to skip them for a few waterings, sometimes that's what it takes.

In addition, i've seen upward leaf curl come shortly after this stage, in essence they (the plants) are trying to shade themselves from the light, due to some/all of the issues mentioned up. I mis-diagnosed it as broadmite, because i first noticed it outside between moving them in and out, and took the wrong precautions. So that's another thing to consider. What you have the basics down it gets easier from here. Best of luck

Under normal light, still not sure about wtf is going on but i am going with overwatering and PH issues

Doesnt look like overwatering there, looks like sulpher or N deficiency. I would add garden gypsum or epsom salts to next watering.

Turns out it's a Zinc deficiency, compounded by high PH.

http://www.theweedblog.com/how-to-recognize-zinc-deficiencies-in-marijuana-plants/

Mystery solved!