New growth yellowing, what's going on?

[Shneex0338]

Hey guys, so the new growth of my autoflower (orion f1) seems to be yellowing for some reason.

Temperatures around 24-28°C at daytime, 18-22 at night. Humidity 45-55%. Day 27 after germination, Orion F1 Auto. Nutrients are everything from Biobizz, only used half the recommended dose of fish mix until now. Soil is Biobizz all mix, 25L fabric pots around 20L filled. Light is a MarsHydro ts1000 at 150W, 100% usage at around 60cm light height. pH is at around 6.8 in soil.

 

[SoOrbudgal]

Can you see what your asking us to look at with these dark pics?:nah:

 

[Bluey]

It's hard to say but I am thinking it's in flower and trying to reveg.

Also, it's quite marginal and I may be wrong, but you may be starting to suffer from a very small magnesium deficiency but I'm only guessing as plant symptoms at the start of that vary plant to plant.

 

[Shneex0338]

2 day update:

The yellowing seems to get worse, this time with better lighting. Any ideas? I watered yesterday with some CalMag, TopMax, Bloom & Grow (Biobizz line), recommended dose for autoflowers. pH seems to be at around 6.8 so far (Soil).

 

[Rwise]

Click on the link "Plant Problems" (https://www.growweedeasy.com/cannabis-symptoms-pictures) then view the 3 links to yellow leaves, read all that may apply. More info than I care to typ.
For soil the PH should be between 6.5 and 6.8 in flower.