15 Plant Grow Leaf Edges Curling Up Ward?

(NOT A HYDRO GROW)

PLANTS: 15in

POT SIZE: 2-1/2 gal pot

LIGHTS: 1000 HPS

TEMP: 79-89

LIGHT HIGHT: 15in away

SOIL: coco soil

NUTES: A-B nutes every 2 days

WATER: R/O water PH at 6.0

RUNOFF WATER PH: 5.0 PPM's 665

this is a 15 plant grow the leaves are curling upwards on the sides like a taco not all of the plants are curling just 1/4 of them. whats wrong with them.

is it cause the ph runoff is so low at 5.0?

I think you need about 6-6.5?

PH sounds about right to me. Do you have a cool tube on that 1000W light? If not, I can't imagine how you have them 15" from the light.

^That's my question, as well. Looks like heat stress.

HEAT STRESS!!! move that light up, maybe 24in. to start and then work your way up or down to where its right.

this is the light. the light stays so cool it has a peace of glass and its hooked up to a blower and it vents outside so its not the heat or is it? they have been under the light for awhile and only like 4 to 5 out of the 15 plants r doing it.

http://www.bghydro.com/BGH/customkititems.asp?kc=HLHPS10SMXXXL&eq=

Where are the effected plants located? Are they the ones getting the most light intensity? If so, there's your answer. At any rate, that's a little too close for a 1000 watt HID, at this stage in growth. You are at least tripling the output of the sun(In the U.S. anyway), directing it at plants that aren't strong/healthy enough to make use of it, even if the heat is/was fine. Back it off to 2' or so, and you'll still be exceeding the sun's intensity, yet reduced enough so that your plants aren't taking a major beating. Save the overkill for mid-late flowering, where it's needed most....producing dense buds.

Also, with that kind of intensity, you should consider adding CO2, and take max advantage of it.

usually this kind of problem is HEAT related but it is caused by the humidty being too low and the VPD vapour pressure deficit being all screwed up.

a 1000w not air cooled should be 24-36 inches away from the tops to not cause problems.


i just read about VPD and leaf curl problems. your heat is causing the surface temp of your leaves to be high thus causing less humidity on your leaves and more pressure which is why they are curling.


solutions

go air cooled

or

raise lights

or

humidifier .


J

my light is aircooled 6inch duckting hooked up to a blower and vents outside there is like no heat coming off the light i can touch the outside of the reflector and theres no heat at all.


i also got a 150 watt hps grow gowing and the humidity is at 39% and my plants love it and for the 1000 watt room the humidity is like 39 to 44 so what worng with them? could this be a ph runoff prob by any chance or is it for sure heat stress?

then look at your relative humidity at leaf level..

low RH will cause this problem even if your temps are 75F


J

ok and when i check whats to low whats to high? and if to low how would i raise it?

the best RH
VEG - 50-60%

FLOWER 35-50%

too low would be anything below 25%

Too high would be anything above 65%

to raise RH either use a humidifier , lots of damp towels hanging around, a bucket of water with a wick in it and fan blowing across it.

to lower RH dehumidifier or raise temps.

J

^Hey J, I'm glad you clarified that the problem was indeed heat(and possibly humidity) related. After re-reading my post, I made it sound like I was blaming the light intensity, itself, when I should've clarified that the area of highest intensity, is going to be the area of highest heat, and should be the area focused upon, when adjusting his lights.

jawbrodt said:

^Hey J, I'm glad you clarified that the problem was indeed heat(and possibly humidity) related. After re-reading my post, I made it sound like I was blaming the light intensity, itself, when I should've clarified that the area of highest intensity, is going to be the area of highest heat, and should be the area focused upon, when adjusting his lights.

Click to expand...

no probs bro.


i just knew as i literally just got done reading the article about RH and VPD's and there is a pic of a plant with exactly the same leaf cupping and what is causing it.

A BIT OF GOOD FORTUNE FOR THE OP lol

we could all use some every now and again


J

jondamon said:

the best RH
VEG - 50-60%

FLOWER 35-50%

too low would be anything below 25%

Too high would be anything above 65%

to raise RH either use a humidifier , lots of damp towels hanging around, a bucket of water with a wick in it and fan blowing across it.

to lower RH dehumidifier or raise temps.

J

Click to expand...

what do u mean by a bucket of water with a wick in it? wats a wick

a wick is a piece of cloth that is half in the water and half out it allows the water to evaporate quicker.

it could be a towel , shirt , dish cloth etc.

did you test the RH at affected area?


J