Cal/mag Def?

[Tacostand916]

Got some new SD and GSC clones. Pretty tall 12" had some thrip damage, dunked them into a bucket of water with dawn fish soap and pro-tek silica.

I transplanted them in Cocogro, prewashed with 80ppm tap water with mykos
2 days after the transplant and 600ppm feeding of Maxigrow. Start noticing streaks of brown down the leaf after day 3. Usually i just up the feeding to 1000ppm and it stops. But since these dont have an established root system, i want to target the issue without overfeeding. I just did foliar spray with cal/mag +. Will add cal/mag+ to next feeding which is tomorrow morning. The issue is with 3 Sour diesels and 1 girl scout cookie.

Ph 6.0 in 5.8 out.
315w 4200k CMH 24/0
600ppm Maxigrow, 68 degrees F 6.0ph
Foliar feed with CalMag+
Cocogro in 1 gallon pots

Any ideas would help. To me, it looks like cal/mag def but since its my first time. I want to make sure.

 

[crimsonecho]

https://www.growweedeasy.com/ph-fluctuations-cannabis

Seems exactly the same

 

[crimsonecho]

If you calibrated your ph pen and sure you are getting correct readings maybe this is your problem then

https://www.growweedeasy.com/potassium-deficiency-cannabis

 

[MW7945]

How often are you watering, and how much runoff do you get when you water?

 

[Homesteader]

They look like they need to be fed something with nitrogen

 

[Tacostand916]

How often are you watering, and how much runoff do you get when you water?

Every other day with 20% run off. I try to wash out any left over ubused nutes.

 

[Tacostand916]

They look like they need to be fed something with nitrogen

They do look a little light on nitrogen in the photos but i believe its due to the new growth and white balance. They are actually fairly dark green outside of the new growth.

 

[MW7945]

Every other day with 20% run off. I try to wash out any left over ubused nutes.

Water daily, or even more ideally twice a day to runoff. Should take care of your issue.

 

[Tacostand916]

I increased the feeding rate to once a day at 1000 ppm with significant runoff. Seems the issue has stopped as all the leaves are perked up and no more additional damaged leaves appearing. Slow growth but progressing positively. Ill be sure to prewash the coco next time with cal mag instead of just tap water. I believed a combination of things occured, a cal/mag defficiency and large ph swings. I corrected my method to find ph runoff. Instead of collecting an aggregate of all runoff, i collected runoff of just one plant. Readings were off by .7 ph. Whereas if i just tested the entire tray runoff, it was .2

Thanks for the help guys. Much appreciated.

 

[MW7945]

Runoff testing isn't really a great method of checking pH. a slurry test will be more accurate. Don't worry too much about it though. Just keep watering with proper ph

 

[heisen]

Check for bugs