Pale green leaves with purple tips

[ChippyMalone]

I'm growing from seed in a new grow tent. My largest Indica seedling is about one month since sprouting and its leaves are beginning to show a slight bit of purple on the tips as well as a bit of yellowing, especially compared to others germinated a week earlier. The purple may just be the indica phenotype that is more apparent when the leaves are more pale.

Up until yesterday, these had not received any ferts other than a very light bit of sea weed extract when they were transplanted to the gallon container about 2 weeks ago. Yesterday, we began at "week 2" of the Fox Farm published schedule.

I did not give this seedling any excess nitrogen until I topped it with the FIM method yesterday, as I like my plants to start out with the minimal amount of stretch I can achieve. From consulting various sources, I have concluded that this is likely just a simple nitrogen deficiency, and one that might be quite expected at this moment in the plant's life considering how it has been cared for.

As it was fertilized yesterday, I will do nothing and simply observe over the next few days to see if the additional nitrogen from yesterday was the solution to this problem. Any comments from experience growers would be greatly appreciated.



Specific growing details below photo. Top plant is the one with the issue. Bottom for comparison.

SOIL GROW

Strain - Indica
# of Plants
Grow Type - Soil: 1:1 FFOF:FRFHF
Grow Stage - Vegetative
Bucket Size - 1 gallon
Lights - LED
Nutrients - Fox Farm 3 part kit plus home made worm casting tea
Medium - 1:1 Fox Farm Ocean Forest:Fox Farm Happy Frog
PPM - n/a
PH - 6.0
RH - 40%
Room Temperature - 72'-78'F
Pests - None Known

 

[Antics]

Your PH is too low for soil. Bring that up to 6.5. To make sure your meter is properly calibrated, you can use distilled white vinegar, and the PH should read 2.4 (any other vinegar types will have a different PH).

RH could stand to be a little higher for Veg, 50-70%, BUT growing at 40% through the whole grow isn't a deal breaker. You won't have have an optimum environment, but it's completely feasible.

FFOF is a fairly hot soil, and you shouldn't need nutes quite this soon IMO.

 

[CareStaker]

Antics hit on one point. Additionally, they both appear to have moderate water stress. Low RH and overwatering are often the cause.
I would let them dry out to where you can still transplant them, and then put them in bigger pots, and then drench them with just water pH'd to 6.5 - In the new pots, mix in an extra 20% of perlite to the FFOF. You want to get them to a drench-to-dry cycling as this is how they breathe.
'n