New Grower Genetics or Deficiency or...?

[SHRED]

Here's some close up shots. Notice the tips of the leaves are twisting. Some 360 degrees.
I haven't noticed any decline in their growth compared to the others in the room.


It's happening on a Northern Lights auto and a Fast & Vast auto. The other two, a NL and a F&V don't show any signs of this. I've backed off the nutes by 2/3rds last feeding and the last watering was pure water and that was yesterday.


If anyone has encountered this I'm curious what it is.
I worry too much but I want to catch something early if I can.
Any advice from those who have seen this would be appreciated.


--


Northern Lights:
http://www.herbiesheadshop.com/vision-northern-lights-autoflowering-feminised-seeds-4402


Fast & Vast:
http://www.herbiesheadshop.com/heavyweight-fast-and-vast-autoflowering-feminised-seeds-4648


Soil:
50/50 mix of Fox Farm Ocean Forest and Happy Frog with a Happy Frog core in 3 gallon fabric pots. I added about 2 inches of perlite at the bottom of the pots first for drainage.
Lights:
For early veg: 2 - 2' x 4 bulb T5HO fixtures on 20/4 light cycle.
For veg/flower:
Mars Hydro 2 900w LED.
Space:
Grow space about 30"x30" x 5 feet.
Nutes:
Using Grow More nutes starting very diluted. 16-16-16, Jump Start, and Maxi-Cal.
As they flower I'm adding 4-26-26 and Hawaiian Bud.
Also using rain water I gathered in my rain barrel.
http://plantsthatproduce.com/guide-nutrients-for-cannabis.html#275




And here's the plants that aren't affected:

 

[Grim Reefer]

Hello Shred. That looks like heat stress to me. What are your temps? how many plants are effected? How close are your lights from the top of your plants?

 

[briman]

Genetic. A few other gardeners have the same stuff going on. Nothing to worry about.

 

[SHRED]

Hello Shred. That looks like heat stress to me. What are your temps? how many plants are effected? How close are your lights from the top of your plants?

Thanks GR however I don't think it's heat related. Temps in the 70 to 78 range. LED is 20 inches away.

 

[SHRED]

Genetic. A few other gardeners have the same stuff going on. Nothing to worry about.

That's what I was thinking considering two others are getting the exact care yet show no signs of this.

 

[virginia gent]

That's what I was thinking considering two others are getting the exact care yet show no signs of this.

same thing is happening to my cheese candy's.

 

[BigBowlBaggins]

Do a flush on the 2 affectd plant and grab a sample of the runn off as soon as it leaks into the tray. Need to know the ppms and ph please. Also before doing this just a couple questions. Have you recently transplanted? Whats your humidity?

 

[SHRED]

Do a flush on the 2 affectd plant and grab a sample of the runn off as soon as it leaks into the tray. Need to know the ppms and ph please. Also before doing this just a couple questions. Have you recently transplanted? Whats your humidity?

No transplanting in this grow. Humidity hovers from 45 to 70.

 

[SHRED]

Do a flush on the 2 affectd plant and grab a sample of the runn off as soon as it leaks into the tray. Need to know the ppms and ph please. Also before doing this just a couple questions. Have you recently transplanted? Whats your humidity?

I don't have a TDS meter. I figured using rain water and the suggested nutes I'd be okay on the ppm's. I may not sweat it this grow but if I do get a TDS meter do I use RO water and how much should I pour through my 3 gallon pots?

Also, I do pH adjust my water AFTER I mix in the nutes. The nutes drop the pH to around 6.1 so I adjust it up to 6.5 to 7.0.

 

[virginia gent]

Did the temps ever get below 60f at night ? Do you leave a small circulating fan on at night ?