Is the soil newly made ?
Looks like just new growth but i see burnt tip
On the new growth so it may be too hot
Edit I took a closer look no burnt tips sorry
It should get through it
Have you used living soil befor and who’s recipe did you use
It’s a local store bought soil called apsu. I cut it with a little promix that I pre ammended with dr.earth. second time with this soil. I may have had the same deficiency in flower last run. Same genetics same soil.
Potassium? Calcium? I agree I’m not too worried yet soil life may not have picked up yet
Are you using Calmag?
nothing but a little recharge with wetting agent so far.
To me it looks like a mag issue. Check your ph and if its in range (maybe re calibrate your ph meter first) add a little calmag or Epsom.
Thank you for the response. I’m new to organic soil growing and I still haven’t figured out how to take soil ph. All I have is a bluelab ph pen for hydroponics. The living soil bag said no need to ph. I think my tap comes out about 7 iirc.
I’m fairly sure some Calmag would sort that blotchy leaf problem
In all honesty I don’t know much about organics and soil. I’m manly hydro or coco but a deficiency is a deficiency. Ph is usually the culprit as if its not in range a lockout occurs. Eg - if calcium is lockedout other elements like iron are not available to the plant.
I’ll try to check the soil ph with my bluelab pen
Water till runoff then check that. 
A proper slurry test and your trusty BlueLabs pen.
Easy peasy. 
Epsom salts and gypsum are your friends, mix both into your soil before planting in it. Among other things obviously, but mag def is real, and epsom sorts that all out. Calcium runs the entire show, 