Intervenial chlorosis on big fan leaves under Citizen COB lights

[JHake]

Hello RIU.

I'm on the learning curve of a 180W Citizen COB light.

Right now i'm on a mixed space with HID and the Citizen. All plants are clones, although the ones under the led have a worse potting soil mix.

The ones under the COB show leaves like this one.
Levels of Calcium in the potting mix of these plants are poor compared to the living soil mix i normally use.

So i believe it has something to do with too much light intensity and not enough energy (nutrients) in the soil, but that's just a guess.



Thanks in advance.

 

[Darkoh69]

Whats in your living soil mix?

 

[yummy fur]

There's no such thing as a citizen cob learning curve for an led light. Completely normal, you can always find something on a leaf somewhere to worry about.

 

[JHake]

Whats in your living soil mix?

My main mix has Calcium Carbonate and Gypsum, while the other mix is more like a standard potting soil with Dolomite instead of Calcium Carbonate and without gypsum

 

[Billy the Mountain]

Hello RIU.

I'm on the learning curve of a 180W Citizen COB light.

Right now i'm on a mixed space with HID and the Citizen. All plants are clones, although the ones under the led have a worse potting soil mix.

The ones under the COB show leaves like this one.
Levels of Calcium in the potting mix of these plants are poor compared to the living soil mix i normally use.

So i believe it has something to do with too much light intensity and not enough energy (nutrients) in the soil, but that's just a guess.

View attachment 5138813

Thanks in advance.

That leaf is a poster-child for a Mg deficiency

 

[visajoe1]

Could be:
-MG deficiency
-improper PH (MG needs 6-7ph)
-combination of both

 

[1212ham]

Mg deficiency. I'd give a foliar spay before lights out with epsom salt in RO water. Some say 1 tsp/gallon and others use 1 tbsp.

 

[JHake]

I thought Mg def showed on lower leaves first.
I normally use tap water; will go with AC water and added CalMag on these plants and see what happens. Foliar Mg also sounds like a good try.

 

[Darkoh69]

My main mix has Calcium Carbonate and Gypsum, while the other mix is more like a standard potting soil with Dolomite instead of Calcium Carbonate and without gypsum

So on one hand your mixing calcium carbonate & calcium sulfate(Gypsum) with potting mix, & on the other your mixing cal/mag carbonate(dolomite) & potting mix & people on here still say you have cal/mag problems! What is it with cannabis forum types & their fixation with adding cal/mag to anything?

 

[FirstCavApache64]

So on one hand your mixing calcium carbonate & calcium sulfate(Gypsum) with potting mix, & on the other your mixing cal/mag carbonate(dolomite) & potting mix & people on here still say you have cal/mag problems! What is it with cannabis forum types & their fixation with adding cal/mag to anything?

What would you say is causing the issue with the leaf then? I've had that exact same problem before two grows back. It straightened out when I transplanted into a bigger pot but I'd like to know what you think is causing it.

 

[Budzbuddha]

Water used ? …. If you ran tap - calcium would be covered.

 

[FirstCavApache64]

Me or the OP? Mine was well water with plenty of Calcium, I believe, based on previous grows never showing any signs of a Calcium deficiency. The soil was Roots organic with Dr Earth 4-4-4 in a 1 gallon pot. My best guess was too small of a pot drying out really quickly and causing the nutrients to concentrate in the tips and screw up the whole plant. I never did figure it out for sure though and would love to know. Transplanting to a bigger pot fixed it right up.

 

[Darkoh69]

What would you say is causing the issue with the leaf then? I've had that exact same problem before two grows back. It straightened out when I transplanted into a bigger pot but I'd like to know what you think is causing it.

I just had an hour or so long soul search & reflected on how in my last response I sounded like one of those know it all keyboard warriors everyone including myself hates. I then had a deep dive in google on the effects of lime added to soils both potting mix & soil outside. I’ll be the first to admit its a rabbit hole Im desperately trying to crawl out of. Please disregard my last post in this thread. & to the Op, best of luck diagnosing your issue

 

[JHake]

Water used ? …. If you ran tap - calcium would be covered.

My tap water has calcium carbonate but...is it water soluble? And on top of that, the water has a 7.2pH.

As far as i know i need acidic water for the CaCO3 to react.

I remember doing a DWC with tap water and salts lacking Ca. Tap water wasnt enough in that scenario and had to add water soluble calcium to the solution.