Cal, Mag Defficiency or both?

[TheObserver]

Hey guys-

So I have been having a fairly healthy and hardy grow so far with minor problems that I and you have helped me troubleshoot. However the day before I turn them I have noticed that there is some kind of deficiency spreading. Please reference the images below. I have 2 plants running the same feeding schedule and connected through a main reservoir, so everything is shared between the two ladies however one has begun to increasingly develop these dark necrosis spots. They appeared a while back but were so small and never spread so I didn't bother paying attention to them. After the last rez flush I turned the plant and noticed that there were many more than I thought!!

One thing to note is that the plant in questions has also had several leaves develop throughout it's veg cycle that had pinholes or tears naturally forming. With this in mind do you guys think this is a Cal or Mag defficiency?

I have added some Cal/Mag to see if this will help.

This is their 5th week in veg and I was going to turn them to 12/12 for the new year but am wondering if I should let them recover before doing so, thoughts?

Thanks,

Plant #1 - showing efficiency

This is plant #2 next to this one mostly healthy but developing a bit of a deficiency as well?

 

[BuddroGreen]

Yes, it looks like a cal-mag issue. If you're using RO water this is expected, if you're using RO water make sure to add cal-mag first before adding nutes.

 

[Bayouboy]

Are you seeing any purpling in the stem or stalk of the plant. Does the stem and stalk show to be purple in color and also the way your leaves are curling up you may have a ph issue... that leaf is also showing signs of light stress how cloae are tour lights

 

[Kal1424]

Are you seeing any purpling in the stem or stalk of the plant. Does the stem and stalk show to be purple in color and also the way your leaves are curling up you may have a ph issue... that leaf is also showing signs of light stress how cloae are tour lights

I have my stems and stalks looking purple, but my PH has been in check... mostly between 6-6.6

see my photo and my problem:

 

[YAYA420]

so what did it turn out to be ?
this is in soil im guessing right ?

 

[SharkByte]

after READING your post, i see your not in soil. This being the case, your PH is too high for hydro growing, cal+mag is eaten by the plant in the 5.4-5.6 PH range. sitting at 6 PH is not letting your ladies take in the needed nutrients.

Next time run lower PH.

 

[Kal1424]

cal+mag is eaten by the plant in the 5.4-5.6 PH range.

How certain are you about this info? I have read different numbers in different places. I have read on forums that its absorbed at 6.0 and i have read that its absorbed at 6.2 this would be good info to have accurate. Anyone else can chime in here please?

Here is an article that says differently...
In hydro, calcium is best absorbed by the roots in the 6.2 - 6.5 pH range (in hydro, it's generally recommended to keep the pH between 5.5 - 6.5, but calcium specifically tends to be best absorbed above 6.2)
https://www.------------.com/calcium-deficiency-cannabis

 

[SharkByte]

I stand by my statement. 5.5 for hydro.

 

[Kal1424]

Thats cool mate. For my comfort, I need more research I think as most stuff I have read says that Calcium and Mag are absorbed above the 6.0 threshold. Lower and its locked out.

There is also a growing trend out there that Cal/Mag additive is not even necessary in a DWC soup. I am not sure about that if you use RO water... but for tap water, I would have to experiment to know for sure, but I can see why you would not need it as the biggest additive in city water is Cal and Mag.

 

[SharkByte]

theorycrafting is fine.
the balance of nutes