Can you help me identify this damage? I'm at a loss, trying to collect info...

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Binary

Binary

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First grow, really learning a ton -- but the more I learn the more I realize I know very little! Would really appreciate some help.

Basic setup:
  • Strain is Jean Guy, grown in Coco Coir (which was buffered with Calmag)
  • It's in an airpot
  • Cabinet VPD has been between 0.8 and 1.1
  • Light is a Migro 100 with dimmer, 18/6 schedule
    • About 22k lux at the canopy
  • Average temp in the past 6 hours has been 26.30 C, max 28.21 C
  • Average rH 64.82%, max 70.47%
  • Currently on day 24.
I've been following the instructions on cocoforcannabis.com, which have me watering when the lights are on, and again 10.5 hours later. The instructions given are to mix nutes into water per vendor instructions, and to adjust to EC, and then pH. So I've been mixing:
This yields a solution with an EC of about 1.8. I've been diluting it down with CalMag water (still at 2ml/L), to get it down to EC .9 to 1.0, then fixing pH. This resulting solution, is the one I feed per the cocoforcannabis schedule. I water until I get a 20% runoff, which is promptly drained out of my cabinet.

I had a few hiccups along the way.
  • I learned about VPD in another forum, and since then I've built myself a system with a RaspberryPi and an SHT30 sensor to monitor/manage it. It shoots me text messages if it isn't trending right, so I can go tweak the AC Infinity fan limits. Prior to this, the fan crapped out once or twice and stopped venting, which caused some 90% rH. Could some of damage have been caused by a bout of extremely high humidity?
  • I potted up from a nursery bag on Monday, and getting the plant out of the darned thing caused a very small amount of root damage at the bottom. I potted into a "Dirt Bag" fabric bag at that point. By Wednesday, I saw that the "Dirt Bag" was retaining a lot of water at the bottom, and was much drier up top. So I swapped it out into an AirPot. Wet-pot problem solved, but I imagine the plant probably didn't like this?
Aside from this, I'm not sure what I could be screwing up so bad that the plant exhibits this kinda damage. Really sucks, I want this to work! Coco is moist, has calmag, pH seems right...help!

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Binary

Binary

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18
Alright thanks. I have indeed been getting lots of runoff, and I mean, I've been following the instructions to a tee. Is a 0.9 EC too high? Should I try to get it down to 0.4 sort of deal?

Looking at this guide, https://www.cocoforcannabis.com/watering_coco/ - they write:

Every time you water cannabis in coco, you should saturate the entire volume of the media. Remember that even at the seedling stage there is no real risk of over-watering. Properly conditioned coco retains adequate oxygen for the roots even when it is saturated.

Saturation is important to prevent salt build-up in the media which can burn your plant. The water that moves through the media and ends up as run-off is the mechanism that prevents salt build up. If the media is not saturated, then there is no water moving through it and salts accumulate
Click to expand...

Later on they write:

Nutrient solution should be applied during events which saturate the media and produce run-off. After each event there should be an interval to air-out. The interval can be as little as 3-4 hours during peak needs.
Click to expand...

So I was reluctant to believe it was related to overwatering, in fact, I was worried that it was a deficiency. Some of the photos looked like Calmag problems to me -- but I'll trust your eyes more than mine...

In the cocoforcannabis site, they try to get you to ramp to 1.0 EC early on, I was still under...

I'll start lowering EC gradually to see if I can stop this mess. I read that a sudden EC change can really shock the plant - true?
 
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One drop

One drop

Bush Doctor
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Binary said:
Alright thanks. I have indeed been getting lots of runoff, and I mean, I've been following the instructions to a tee. Is a 0.9 EC too high? Should I try to get it down to 0.4 sort of deal?

Looking at this guide, https://www.cocoforcannabis.com/watering_coco/ - they write:



Later on they write:



So I was reluctant to believe it was related to overwatering, in fact, I was worried that it was a deficiency. Some of the photos looked like Calmag problems to me -- but I'll trust your eyes more than mine...

In the cocoforcannabis site, they try to get you to ramp to 1.0 EC early on, I was still under...

I'll start lowering EC gradually to see if I can stop this mess. I read that a sudden EC change can really shock the plant - true?
Click to expand...
Yes just lower ppm gradually yes big shift can cause shock . Regards Od .
 
Aqua Man

Aqua Man

26,480
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Nevermind I seen it.

What size pot and how much are you giving them for each water?

What light are you using and how close is it? You can't be over watering IMO but are you temp adjusting the water before feeding?

EC is about right maybe 500ppm but im curious if you are watering enough to get good runoff every time.

What Is the runoff ppm and pH?
 
Binary

Binary

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  • Getting about 20% runoff with each watering.
  • Giving 240ml per watering
  • Runoff is between 0.9-1.0.
  • pH is about the same as inflow, between 6.1 and 6.2 EC
Going on the advice above, I diluted today’s feed to 0.4 EC, corrected pH. Runoff was still at 0.9 EC.

Water is from a RO system, 0 EC

Light Is a MIGRO 100, it’s about 24 inches from the plant, dimmed to about 30%. 22k to 25k lux at the canopy.

Thanks for the help!
 
cemchris

cemchris

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What order are you mixing all of those nutes starting with the plain water? You using the AN 3 part correct? IS it the PH perfect stuff?

They have a good guide on that site for mixing order. I would PH down after Silica tho before Micro if using it.
 
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