Diagnostic help please: W Widow fan leaves dying, crispy, rusty, curling up

[CaptainCanuck]

Thanks in advance for any help! I'm a newbie grower and am puzzled.

I successfully ran this White Widow once, and the plants in trouble are 7 clones from the first plant.

They are all showing the same symptoms, despite being a test grow in several different media with different fertilizers.

I have: 2 in perlite hempy buckets (one getting Canna Vega nutrients, one with time released MGro), 3 in soil mix (50% peat, 20% perlite, 20% composted fish/forest fines, 10% worm castings), 2 in a "SeaSoil" potting mix similar to the custom peat mix but based on coco. The soil and coco plants have either received just plain ph'd water, or Canna Vega or MGro time release.

So far I have tried to be patient and observe, thinking it may be normal with clones and they would grow out of it. I flushed 3 of the plants with ph'd water but they are no better than the others.

SOIL GROW

Strain - Seedsman White Widow
# of Plants - 7
Grow Type - Soil, Perlite Hempy
Grow Stage - Vegetative, early flower
Bucket Size - 1-3 gallon
Lights - 900 Watt full spectrum LED
Nutrients - Canna, MGro time release
Medium - 3 different, see above
PPM -
PH - 6.0 for Perlite hempy, 6.5 for soil mixes
RH - 60% to 75%
Room Temperature -65-75 F
Solution Temperature -65
Room Square Footage -4'x4'
Pests - None Known

Problem: Leaves are curling up, drying out and getting crispy in all media with all feed programs. Seems to be slightly worse with plants put into 12/12 a week ago. Affects older fan leaves and those towards the middle of the plant, but not new growth.

 

[KingJohnC]

What are you using as your water source? You want pH 5.8 for hydroponic and soiless (peat moss and coco coir) and pH 6.5 for soil. The leaf damage appears to be a calcium deficiency and possibly something else. You are adjusting your pH too high and locking out nutrients.

here is a nutrient availability chart

here is a cannabis leaf deficiency chart

here is the Cannabis Plant and Pest Problem Solver and the Plant Abuse Chart

Cannabis Plant and Pest Problem Solver - Pictorial

Plant Abuse Chart

 

[CaptainCanuck]

Thanks KJC for the quick response!

In answer to your question...I'm using tap water left to stand for 24 hours.

I'll bring the "hydro" plant feed down from 6.0 to 5.8 and see if that helps the hempys.

Oddly, the mother of these clones was raised entirely on the tap water/Canna Vega feed ph'd to 6.0 and she never showed any of these symptoms.

I was assuming all of the "soil containing mixes" with the peat or coco in them were "soil"...so those I'll bring down from 6.5 to 5.8 ph. Thanks for catching that.

The second remaining oddity is that the plant in a real soil with a small amount of peat and perlite is also showing these symptoms at ph 6.5...

 

[KingJohnC]

After allowing some time for your plants to recover if they do not show improvement I would consider using a calcium and magnesium supplement.