6 clones different deficiency?

Cabrone said:

I have been at this a little while now. Finally switched to dtw coco. Very pleased with the results compared to promix. Ok, I have six clones from the same mother. At the end of week 4, 3 of them showed calcium deficiency in some of the fan leaves, rusty yellowing in the margins. I adjusted the ph a little higher and it has stopped. The other 3 plants have no sign of any issue. In a 4x8 tray, all in the same environment, and feed schedule, from the same reservoir. 78°F, 46% rh, ph 6.5, 800ppfd, 1.3 ec
Wtf, why only 3, Any ideas?

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Understanding VPD and Transpiration Rates for Cannabis Cultivation Operations

This article explores how vapor pressure differentials (VPD) affect transpiration rates in cannabis plants. Understanding of VPD at different temperatures and relative humidities, and its effect on this process, is important to gain maximum plant growth.

www.cannabissciencetech.com

calvin.m16 said:

I use MaxiGro @ 1.0-1.2 EC 5.6-5.8 pH and MaxiBloom @ 1.4-1.6 EC @ 5.8-6.0 pH in coco with RO filtered water.

EC/PPM is kinda irrelevant without knowing what source water and fertilizer/products you're using.

Suggestions:
Reduce PPFD to 300-500
Reduce pH to 5.8-6.0
Increase humidity to 60-65%

Take a look into VPD, your running a very high VPD around ~1.8 That will stress plants and show weird symptoms like deficiencies due to over transpiration.

Understanding VPD and Transpiration Rates for Cannabis Cultivation Operations

This article explores how vapor pressure differentials (VPD) affect transpiration rates in cannabis plants. Understanding of VPD at different temperatures and relative humidities, and its effect on this process, is important to gain maximum plant growth.

www.cannabissciencetech.com

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