In flowering the prime uptake starts wk5. You’ll see people at wk6 asking what’s the deficiency.
Noted, thanks! 
So basic rundown for flowering diagnosis based by stages.
Wk2 - Ca
Wk3-5 Mg or Ca
Wk6-9 K
Thanks again, bookmarked! 
Now, all I have to do, is remember that when I’ll need it! 
A bit easier to understand that the Mulder’s Chart! 
The Mulder’s chart takes some practice and you have to know what lines to exclude from diagnosis by stage demands and food inputs
Used a soil probe and ph was around 7
Thinking it’s maybe ph? We use fabric pots and it drys fairly quick
Don’t trust cheap soil probes! Learn to feel the weight of the pots just after watering and when they are dry. On a young plant like that, overwatering will cause those symptoms as well as nute burn . New growth appears to be healthy . 
Agreed I was just gonna say that. About the probes and the new growth. And I think there’s nothing to fix
There been a few others with young plants in OF get some damaged young leaves then grows out of it, just recently but I forget who.
Yeah it’s fine. Just had a rough start with a bit too much water.
I don’t think we have been over watering but I could be wrong but that does have some yellowing on new growth on the tip of the leaf
Remember, overwatering isn’t how much you give them at a time, but how often and not letting the roots dry enough to breathe. Looks like she’s coming back strong. Once they get roots under them, they will drink way more.
Let’s see it and then I’ll re diagnose if needed.
Will be there this weekend let you guys know then !