Ok, so let me begin by saying I'm not new to the game. Been around a while, and while my knowledge is far from comprehensive I know more than most when it comes to growing cannabis (largely thanks to years of research in wonderful groups like this, reading books, hands on instruction from people with decades of experience, and personal experimentation.) With that said, I'm currently stumped.
I cut a bunch of clones from several very healthy mothers that are proven good genetics from a years long pheno hunt. These plants have been taken to successful harvest several times, with excellent health and wonderful end results.
Those clones started out healthy, but as they age they're showing some truly awful signs of stress that I can't identify.
I've been fighting this for about 6 weeks now and have exhausted my ideas and those I've found through research.
Growing parameters:
Coco
Cloth pots
GH 3-part at 1/3 strength
Using RO water
Supplementing with CalMag
Ph to 6.0 to 6. 1
Temps in low to mid 70s
Humidity 50-60%
Some plants under LEDs, some under CMH, some under HID. Ppfd at canopy ranging from 400 to 800 at various times trying to identify any light issues.
I've examined plants under a microscope and find absolutely zero evidence of pests of any kind.
They are not being over-watered. I have tried various levels of both nutrient density and feeding amounts. Various combinations and ratios ranging from 400ppm to 1100ppm and anywhere from a quart a day to a gallon a day.
Runoff tests good, with pH and ppm coming out where they should.
I have flushed repeatedly with straight water to full runoff a couple of times.
I've experimented with a few and let them dry out almost completely.
I've treated with several beneficial innoculants, both bacterial, enzymatic, and fungal.
I've used a couple of natural foliar sprays, including a neem based product, an all-natural organic plant-oil product, and a sulfur based product. I even went nuclear on a few in quarantine with hard core chemical insecticides (and when that didn't have an effect I discarded the plants.)
I've changed pH up and down on a few. I've calibrated my pH meter, and then also double checked for pH accuracy using drops and strips. PH is being raised and lowered with both natural and chemical means on different small test groups (vinegar, lemon, and baking soda to commercial GH up/down.)
The pictures attached show the various stages of progression as the clones age.
Suggestions? Today I'm trying a solid flush with H2O2, but that's the last thing I have to try.
This is in a commercial facility, and I have sought advice from multiple experienced 'master grower' type people whose opinion I highly value, and tried their suggestions with no effect.
I cut a bunch of clones from several very healthy mothers that are proven good genetics from a years long pheno hunt. These plants have been taken to successful harvest several times, with excellent health and wonderful end results.
Those clones started out healthy, but as they age they're showing some truly awful signs of stress that I can't identify.
I've been fighting this for about 6 weeks now and have exhausted my ideas and those I've found through research.
Growing parameters:
Coco
Cloth pots
GH 3-part at 1/3 strength
Using RO water
Supplementing with CalMag
Ph to 6.0 to 6. 1
Temps in low to mid 70s
Humidity 50-60%
Some plants under LEDs, some under CMH, some under HID. Ppfd at canopy ranging from 400 to 800 at various times trying to identify any light issues.
I've examined plants under a microscope and find absolutely zero evidence of pests of any kind.
They are not being over-watered. I have tried various levels of both nutrient density and feeding amounts. Various combinations and ratios ranging from 400ppm to 1100ppm and anywhere from a quart a day to a gallon a day.
Runoff tests good, with pH and ppm coming out where they should.
I have flushed repeatedly with straight water to full runoff a couple of times.
I've experimented with a few and let them dry out almost completely.
I've treated with several beneficial innoculants, both bacterial, enzymatic, and fungal.
I've used a couple of natural foliar sprays, including a neem based product, an all-natural organic plant-oil product, and a sulfur based product. I even went nuclear on a few in quarantine with hard core chemical insecticides (and when that didn't have an effect I discarded the plants.)
I've changed pH up and down on a few. I've calibrated my pH meter, and then also double checked for pH accuracy using drops and strips. PH is being raised and lowered with both natural and chemical means on different small test groups (vinegar, lemon, and baking soda to commercial GH up/down.)
The pictures attached show the various stages of progression as the clones age.
Suggestions? Today I'm trying a solid flush with H2O2, but that's the last thing I have to try.
This is in a commercial facility, and I have sought advice from multiple experienced 'master grower' type people whose opinion I highly value, and tried their suggestions with no effect.
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