Yellowing Chernobyl in Veg Need Some Opinions

[NorCalSivart]

Looking for some help with my plants. I think I have been underfeeding them. Over the past few days they have started to get more upper yellow leaves. It is affecting 2 of the Chernobyl's more than 1 of them.

After transplanting about 1 week ago a few days later the problems started happening. I have since increased the amount of nutrients I am feeding them from 2ml-5ml CalMag. (I am using RO water) Along with the CalMag I have been giving them 8ml Grow. Can't tell if the nutrients are being locked out or not. I am pretty sure my pH is around 6.0 but only have a cheap pH Tester.

The yellowing is affecting the top leaves the most but has slowly progressed down the plant.

I was thinking it might be a sulfur deficiency from what I have seen around but would love some advice. Thanks!

What Strain is it? Chernobyl
Is it Indica, Sativa or Hybrid? What percentages? It is a S/I dominant not sure of the percentage.
How Many Plants? 3
Is it in Vegetative or Flowering Stage? Vegetative
If in Vegetative Stage... How Long? finishing up the 2nd week.
Indoor or Outdoor? Indoor
Soil or Hydro? CoCo Coir
If Soil... What is in your Mix? Mixed coco with perlite.
If Soil... What Size Pot? They started off in red solo cups were in there for 1 week before transplanting to 1 gallon smart pots.
Size (Wattage) of Light? How Many? 2x280W Led Lights
Is it Air Cooled?
Temperature of Room/Cabinet? No hotter than 81 degrees mostly 77-78.
RH of Room/Cabinet? Fluctuates between 40-60% during lights on and off.
PH of Medium or Reservoir? I believe it is around 6.0
Any Pests? No
How Often are you Watering? Every other day.
Type and Strength of Fertilizers used? Botaincare CNS 17 Grow around 10ml and CalMag 5ml
Size or Square Footage of Room? 3'x3'


Here is one plant:

Another Chernobyl that is affected.

 

[FrankFoster]

Flush the shit out of it 3 gallons + and then the last bit of water has the N def nutes, use GROW ratios. I would also add some powdered black kelp to the flush at 1/4 ratios. for 1 full gallon.

So I would say if you are on 24/0 is micro MG def, if you are on 18/6 its probably N def.
But the flush will get you back to zero.

 

[NorCalSivart]

Thanks for the advice. I will flush them when the lights come back on in a few hours.

 

[kiwibloke]

Know this is a little late, but looks like classic iron deficiency . why is another reason . . . .did the flushing work ??? always good to hear what the result was of advice.

 

[kiwibloke]

Know this is a little late, but looks like classic iron deficiency . why is another reason . . . .did the flushing work ??? always good to hear what the result was of advice.

Just going through old threads and I think I'm wrong on the iron . .I think when the photo was taken there was a flash or the grow light was on above . . . anyway my bad !!