Ummm ...

[Waira]

Yoz! ... pardon mate, I seemed to have hallucinated responding here earlier ....

I think it's a combo deal here,... it's definitely relevant that this strain is bitchy and intolerant, even to sub-optimal env. conditions.... evident by the RH% and air movement sensitivity,...
Yoz, that's a metric shit-tonn of lights, in how big an area, and how far away? COB's are fierce beamers, and those CMH's ain't there for the food either! I think the symptoms are related to some light and environmental issues,.. she likes it hotter and drier.... hates the higher RH% range (which will screw with transpiration just as bad as low RH will)... higher temps help with the higher RH%, what's it usually like for RH%?
here's the deal: any combo of overly strong light, overly high/low RH%, higher T, strong air movement can start to put transpiration and light intensity stresses on those upper leaves (also explains why the sheltered leaves are fine)... fuck with transpiration rates (slow/shut it down), and the whole nute/water highway from roots up starts to suffer,...Then come the weird symptoms, usually localized (this looks Fe/Zn defc., but has Ca defc. spotting as well-).... I think you're on the edge of tolerance on some of these things, plus the bitchy nature of this strain (maybe pheno'?), and when you drift off the tolerance range, they react poorly,... Honestly, barring more info about the grow space size and light distances, I think they are the root cause here,... if you can reduce light intensity some, temp, air movement and RH% tolerance may improve,....

 

[Yozhik]

I've raised the 2 x 315W CMH lights.

they were in a 1,5 x 1,0 space, but floor space has now doubled, so the footprint within the light scaffolding is 3,0m x 2,0m.

the grow area - wall to wall - is 3,9m x 3,5m.

I have added GH FloraMicro, and also added some CalMag into the mix.

Early days, BUT there does appear to be some improvement.

More lights are being added too.
2 x 315W CMH have joined the party, bringing the total to 4.

I'm toying with the idea of removing the 3 x COB strips, and running a further 2 x CMH [6 in total]

So end configuration will be either;

4 x 315W CMH, plus 6 x 205W Cree COB strips

OR

6 x 315W CMH

Humidity seems settled at ~60%RH, and the girls seem to be more tolerant of it.

Similarly, temps have also settled lower at 25 C, which also seems more "normal".

We might ... might ... be able to turn this around, slowly but surely.


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[Waira]

Ahhhh, that's some elbow room there mate! ... so, as you know, I'm largely an OD grower, using lights as supplements only,.. you'll need somebody else to analyze the room and lights situation... @BigSm0 .. @Rev. Green Genes ... @Ripper ... @pop22 ..... chime in if you would please!

Yoz, this thread and some others had my brain worm squirming,... stuff I needed to brush up on more, seeing dots connect with environment, symptoms, cause and effect (or is that cause vs. effect)... So, I looked around for more concise info about VPD-- vapor pressure deficit,... and how it affects transpiration, and the interrelationship between it and T, RH%,.... Check out the new article in the Reference section! .... yes, that's me pulling the idea bulb out of my ass!

 

[Ripper]

These sound like Afghani strains. They live heat and no wind . Point the fan up so it doesn’t hit them directly. It looks like you got the rest covered.. they thrive in heat..

 

[Yozhik]

These girls have tested my growing capabilities for sure.
It's been pretty much a case of throwing the guidebook out the window, and listening to the plants.

The COBs have been positioned as supplemental lighting, way up high.
As high as I can throw them on the 2,2m tent frame. So conservatively, they'd be 2,10m from ground level.
The CMH lights WERE about 12 inches away, and have now been raised to double that.
CMH can easily be paced as close as 8" from the plants, so even 12" wasn't pushing the envelope.

"Here's one I prepared earlier ..."​

It seems, fingers crossed, the addition of the FloraMicro and CalMag, plus the lifting of the lights a little, may have all helped in their own special way.
As a result, there now seems to more tolerance to RH% and air movement.
The yellowing of the leaves, while still there, does appear to be dissipating.
It's a matter of time and patience now.

 

[Rev. Green Genes]

I've raised the 2 x 315W CMH lights.

they were in a 1,5 x 1,0 space, but floor space has now doubled, so the footprint within the light scaffolding is 3,0m x 2,0m.

the grow area - wall to wall - is 3,9m x 3,5m.

I have added GH FloraMicro, and also added some CalMag into the mix.

Early days, BUT there does appear to be some improvement.

More lights are being added too.
2 x 315W CMH have joined the party, bringing the total to 4.

I'm toying with the idea of removing the 3 x COB strips, and running a further 2 x CMH [6 in total]

So end configuration will be either;

4 x 315W CMH, plus 6 x 205W Cree COB strips

OR

6 x 315W CMH

Humidity seems settled at ~60%RH, and the girls seem to be more tolerant of it.

Similarly, temps have also settled lower at 25 C, which also seems more "normal".

We might ... might ... be able to turn this around, slowly but surely.


Sent from my iPhone using Tapatalk

Honestly, I am far less concerned with wattage as I am with coverage. 6 300 watt MH lights would rock for vegetavive stage, but I would question the wavelengths for flowering. They are somewhat more efficient than HPS, but have less UV, less far red, and less red. For that main reason I would keep your COB strips and run them for flower only. A typical 400 watt MH light, ceramic or not, will cover 6 sq ft for veg, unless you get them really close like in flower, then you are down to 3-4 sq ft coverage. So if you intend on running them as close as possible, you need all 6, but do the plants need the excess photons that getting the fixture closer produces? not really. That much wattage is already over the threshold for photosynthesis. The only other thing to wonder about is probably penetration, so this is more about grow style and how much you leaf prune than light, but the CMH has great penetration on it's own even at higher distances. You will be getting light from several angles on each leaf, and the cumulative effect of from multiple light angles is massive. I hope this helps.

 

[Yozhik]

Honestly, I am far less concerned with wattage as I am with coverage. 6 300 watt MH lights would rock for vegetavive stage, but I would question the wavelengths for flowering. They are somewhat more efficient than HPS, but have less UV, less far red, and less red. For that main reason I would keep your COB strips and run them for flower only. A typical 400 watt MH light, ceramic or not, will cover 6 sq ft for veg, unless you get them really close like in flower, then you are down to 3-4 sq ft coverage. So if you intend on running them as close as possible, you need all 6, but do the plants need the excess photons that getting the fixture closer produces? not really. That much wattage is already over the threshold for photosynthesis. The only other thing to wonder about is probably penetration, so this is more about grow style and how much you leaf prune than light, but the CMH has great penetration on it's own even at higher distances. I hope this helps.

CMH bulb used for Veg is @4200k

CMH bulb used for Flower is @3100k

COB strips are 4 x Cree CBX3590 @3500k


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[Rev. Green Genes]

One other thing I would say, from growing back to back with HID lights, and LED lights I thought I noticed a lot more scraggly bushy growth from the HID's and a more compact orderly growth pattern with LED's. Some of that is genetic, but I think the COBs will produce more compact plants with a better leaf:bud ratio.

 

[Yozhik]

One other thing I would say, from growing back to back with HID lights, and LED lights I thought I noticed a lot more scraggly bushy growth from the HID's and a more compact orderly growth pattern with LED's. Some of that is genetic, but I think the COBs will produce more compact plants with a better leaf:bud ratio.

Yeah - they definitely have their own unique impact on a grow.

My last journal was a side-by-side with the CMH vs COB.
The result from that is what has driven me to do a combo grow this time.
There were aspects of each type of light i loved.
I'm hoping to make the hybrid lighting environment they could really enjoy and flourish in.

 

[Yozhik]

@pop22 @Waira

I wanted to give a detailed pictorial follow up, both as a THANK YOU to you guys, and also for any others who read this thread.

The girls are greatly improved.
OK - so there are still a few signs of the earlier deficiencies, but that was pretty severe, and to see them now, in such a short space of time - I'm definitely counting it as a victory.

**WARNNG**

These image files might be a tad on the HUGE side.
If you click and click, it will take you to the hosted real image size.
However, one of the things about the infirmary is that its all in the details.

Besides, I know @Waira is a size Queen ...

Anyway, on with the show, and if you compare these pics with the earlier ones, you will definitely see the difference.
The little bit of nute burn on the tips now, is a trade off I'm happy with.
To be honest, its a bit of a struggle to keep the micro level where they demand it, without raising the EC to excessive levels.
It's a real tightrope walk.