Looks like heat stress but isn't. Help!

M

makeitfunky

Member

• Jan 12, 2018

• #1

Hi, my plants are showing signs of heat stress (I think). Leaves curling upwards at the edges but the temps and humidity are fine. What else could it be?

Background info:

Original Glue in 8L pots in Coco.
4th week of Veg.
1000w HPS about 1.2m above canopy.
Temps 25c day 20c night
RH 60%

Feed EC 1.8-2.0
2.5mls/L Coco Specific A+B and 0.5mls/L CalMag
ph5.6-5.8
3 times a day in DTW

I was running in to a cal mag def (I think as was running a low EC 1.2-1.4) So have upped it with a bit of CalMag which seems to have done the trick apart from the leaf curling. Its all over the pant top and bottom so def isnt heat.

Pease see pics and help really appreciated.

Thanks

 

Attachments

• 
  IMG_2953.jpg

  110.8 KB · Views: 11

M

maimunji

Active member

• Jan 12, 2018

• #2

Double check your ph with ph strips. Looks like its off.
Drop cal mag because you are not far away from lockout. 2.0 is extremely high and if you continued to feed with this rates you will overfeeding everything and will finish with crap.

 

M

makeitfunky

Member

• Jan 12, 2018

• #3

I will try that thanks. I have a ph pen that calibrated to 7.0 but maybe it’s off at the lower end?

My tap water is 0.4 so I thought there would be no need for CalMag but I was def having defecencies before. Any more ideas anyone? In case pH IS correct?

Could it be something to do with the Coco?
Also could it be to do with the coco getting cold? Cold air is drawn in near the bottom of the tent

 

M

makeitfunky

Member

• Jan 12, 2018

• #4

Also what nutrient is lacking to cause heat stress type symptoms?

 

Lester Beans

Frequent Flyer

Veteran

• Jan 12, 2018

• #5

Your pH is too high. 6.0-6.1 for coco.

Also you ec seems really high.

 

M

makeitfunky

Member

• Jan 12, 2018

• #6

Thanks I will change the PH to 6.0 and also lower E.C

Do you think CalMag is necessary?
If I add maybe 2mls/L A+B and 0.25mls/L CalMag E.C would be about 1.4 does that sound ok? What would you recommend?

 

Lester Beans

Frequent Flyer

Veteran

• Jan 12, 2018

• #7

That sounds about right. I would def us cal mag.

You caught the issue early so good eye. They should be back to normal very soon.

Make sure to flush some before resetting feed. I would flush with proper pH water.

 

A

Athos

Member

• Jan 13, 2018

• #8

I had the same issue happening to me last run, leaves looked the same as yours. It was pH been too high.