Only the leaf tips got yelow in whole plant.

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gangotri

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Now, I have switched to HPS 400 and to 12/12 three days ago, and added npk 10 days ago. And for one reason or another (or maybe some other reason) the very tips of the leaves are yelow.

It happens to all leaves, from bottom to top, even new growth. But only the tips got yelow. The pot is drying very fast because of the temps and the 12 hour on fan so I am watering a lot more now.

The plant as a whole looks healthy, only those tips are a concearn. I am thinking it may be the npk I added, or temps too high or maybe lack of water. Can U see the yelow tips at the becture below? Any ideas?

DSCN3424.JPG


DSCN3422.JPG
 
gangotri said:
Now, I have switched to HPS 400 and to 12/12 three days ago, and added npk 10 days ago. And for one reason or another (or maybe some other reason) the very tips of the leaves are yelow.

It happens to all leaves, from bottom to top, even new growth. But only the tips got yelow. The pot is drying very fast because of the temps and the 12 hour on fan so I am watering a lot more now.

The plant as a whole looks healthy, only those tips are a concearn. I am thinking it may be the npk I added, or temps too high or maybe lack of water. Can U see the yelow tips at the becture below? Any ideas?

It could be a light nitrogen burn. Or, it could be too hot in the grow area. How hot is it getting?
 
Stoney Bud said:
It could be a light nitrogen burn. Or, it could be too hot in the grow area. How hot is it getting?

SB, I still dont have a termometer, but despite being in the begining of winter, I am in Brazil, and during the afternnons it ALWAYS get very hot here and I do know my closet is getting warm during the hot hours, but by my experience with other plants I thought heat would make the leaves to wilt as it has happened before with other MJ plants also.

Ill try to get a termometer asap. Wich temps should I me at TOP most? in Celsius? My stream is close to Afgan so it should endure high temps right?
 
Mate i use a 400watt hps also with my last grow i had the thing like 18-22inches away from the plants and had heat problems i didnt really know it and my grow didnt turn out the best at the end, thistime i used the hole room with the light over 2 away and the temps are right on 21degrese all the time, see you at the end of your leaves and the tips there kinda pointing downwards i think that your light is to close or the rooms a bit walm. im not saying this is your problem thats just my opinion, try get a termometer asap bro.
 
gangotri said:
SB, I still dont have a termometer, but despite being in the begining of winter, I am in Brazil, and during the afternnons it ALWAYS get very hot here and I do know my closet is getting warm during the hot hours, but by my experience with other plants I thought heat would make the leaves to wilt as it has happened before with other MJ plants also.

Ill try to get a termometer asap. Wich temps should I me at TOP most? in Celsius? My stream is close to Afgan so it should endure high temps right?
23.8 is preferred, but 29 is the highest you should ever go unless you cool your root zone.

Keeping the root zone at 23.8 is the absolute best thing you can do. You can get away with higher temps above ground if you do that.
 
Yeh i didnt know that bout the root zone temp stoney, nice one ill have to remember that, mine are about that 23-25in away seems to work best for me and my enviro. Gangotri i would keep raising it an inch every half a day or something and watch your plants just see how they respond.
 
Stoney Bud said:
23.8 is preferred, but 29 is the highest you should ever go unless you cool your root zone.

Keeping the root zone at 23.8 is the absolute best thing you can do. You can get away with higher temps above ground if you do that.

Thanx Stoney, do you use any good technic for making the root zone cooler? Thermic isolants?
 
unix said:
Yeh i didnt know that bout the root zone temp stoney, nice one ill have to remember that, mine are about that 23-25in away seems to work best for me and my enviro. Gangotri i would keep raising it an inch every half a day or something and watch your plants just see how they respond.

Yeah Ill try that, its now 21in above the tops, dont you think the plant will have less light for growth if I pull it up too high?
 
gangotri said:
Yeah Ill try that, its now 21in above the tops, dont you think the plant will have less light for growth if I pull it up too high?

Yes, optimum growth with a 400 watt HPS is with it at 18 inches from the top of the canopy. However, planning must be done to prevent heat build up that would harm the plants.

This is one of the reasons everyone should research the use of an inside grow room prior to actually growing.

The first grow is always a rough one while learning what *not* to do.
 
I like to find that spot, they might not be getting as much light that far away but i find they dont want to grow tall as fast if the light is any closer.
 
unix said:
I like to find that spot, they might not be getting as much light that far away but i find they dont want to grow tall as fast if the light is any closer.

That's prolly because of the heat. If you move your light higher, it will have a direct result in the quantity and quality of your harvest in bud weight and potency.

It's better to resolve the heat issue and keep the lumens at canopy level at their best.
 
Stoney Bud said:
That's prolly because of the heat. If you move your light higher, it will have a direct result in the quantity and quality of your harvest in bud weight and potency.

It's better to resolve the heat issue and keep the lumens at canopy level at their best.

I see, less light less potency. I think I am rich in lumens anyway, with a 400hps for one plant only in a small place, it is definatelly more than the 2000 per sq/feet. They probably dont have a chart saing how many lumens you loose per inch far from the HPS do they?
 
gangotri said:
a chart saing how many lumens you loose per inch far from the HPS

Yes, I have seen one posted here on this group. Try a search for it. Perhaps someone else knows where it is???
 
According to the chart 21 inches is the highest one can get to be at the optimun distance for a 400hps so Im better fix the heat problem somehow.

lightdistancechart.jpg
 
Excellent man! I'm glad you found it. Yes, if you fix that heat problem, you'll have a perfect solution.

Good luck man!
 

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