WTF is this?! Patterned fan leaf serrations

2nd grow so I'm still noobish but I have done quite a bit of "plant problem" research and I have never seen an example like this. I have been having an ongoing issue that is showing as Cal/Mag/P imbalances but this is a totally new issue or completely new manifestation of the current issue.

My initial thought was heat stress so I turned down the ballasts and raised the lights but other nearby fans are unaffected. I am hoping it is a temporary response from a number of stress events over the last 10days that included defoliation, training, few hot days 85-86f canopy temp, a 12-18hr period with less than an inch of water in the RDWC, timer fuck up that kept at least one light on for 2 days, and then finally flipping to 12/12 the day before I found these.

I am not surprised to see undesirable responses to these events but I have never seen anything like it. Thoughts?

Excess calcium

hotrodharley said:

Excess calcium

Click to expand...

I should have mentioned I am using 20ppm RO water and I have been running no more than 1ml/gal of Cal-mag so excess Cal should be impossible. I specifically cut cal-mag almost completely in veg to observe if a Cal or Mag toxicity was causing a lockout of phosphorus which is ongoing issue that I have been trying to figure out since the previous generations of these plants.

RO water and no cal mag. Then it's calcium deficiency but it's calcium related. Or insects.

Hi Darkness,
Your leaves are also super dark which indicates too much N. What's your nutrient PPM? Whatever it is...lower it ...especially if you're going to add in some Calmag.
JD

Nitrogen tox + light stress.

Just got home, surprisingly the garden looks extra happy and thankfully there isn't any progression of the serrated holes. That was my biggest concern at the moment. It popped up in a matter of 12hrs so I was scared I could be coming home to a trashed canopy.
As far as the ongoing Cal/Mag/P issue, progression also seems to have stopped but I know it will be back. I have narrowed it down to a P lockout and Im pretty sure excess or lack of Cal or Mag has something to do with it. I ordered a cheap Cal test kit. IDK what the proper Cal ppm's are and Google didn't have any quick answers but at least I will have a consistant measure to work from.

looks like sudden severe PH swing....a slow drift is good, a big jump isn't

Roger A. Shrubber said:

looks like sudden severe PH swing....a slow drift is good, a big jump isn't

Click to expand...

Yeah, there has been some of that, not much more than a full point swing but it has gone up and down 3 times in the last 5 days. Due to a scheduled and an unscheduled res change.

DarknessFYC said:

Yeah, there has been some of that, not much more than a full point swing but it has gone up and down 3 times in the last 5 days. Due to a scheduled and an unscheduled res change.

Click to expand...

i've never seen it actually burn all the way through, but i've seen almost the same pattern, pretty bad over night. screwed up and added ph down instead of ph up....knew how much it took, so i added the right amount, of the wrong one

Roger A. Shrubber said:

i've never seen it actually burn all the way through, but i've seen almost the same pattern, pretty bad over night. screwed up and added ph down instead of ph up....knew how much it took, so i added the right amount, of the wrong one

Click to expand...

Yup, done that b4.
Glad I'm not the first to see it this tho, For whatever reason the symmetry and speed of onset was kind of frightening, especially since I've never seen a Pic of anything similar.

these are from groweedeasy but it's the classic pattern

when it happens slowly it looks like that, and spreads slowly, when it's a big ol' spike that happens suddenly.... you get the same pattern with worse damage, apparently up to and including holes

Growweedeasy.com is awesome, I can go and read forums for an entire day but then go to GWE and they have already summerized and condensed every opinion I have read.