Can You Tell Me What Deficiency This Is Please? (pics)

I'm having trouble diagnosing this deficiency (pics). From looking through the net I think it's either Calcium, Magnese, or Magnesium. I have been feeding with CalMag and this has never happened before. I read on another site that you are not supposed to use CalMag in Flower is this true? I don't thinkso. Here's the setup:

4th week of flower
All clones are from Harborside Oakland
This is happening on the Fire OG's & Suzy Q's (high CBD 59:1)

Soil:
Happy Frog & Ocean Forest mix (never mixed for flowering before but had to this time)

Nutrients:
Pure Blend
Sugaree Carbs
Pure Blend Pro
CalMag
Some SuperThrive beginning stages

PH 6.8-7.0
Runoff 6.4-6.5

Any suggestions would be appreciated.

I think its a Calcium def now. This hasn't happened before. How much should I be using per 5 gallon water container in week 4?

She is a calmag slut. But, your ph looks good. Use at least 5ml per gallon. Maybe give them a double shot this week. Safe to use during flower, yes.

Haha that's what I was thinking! I told them them they are big girls and I'm probably not feeding them enough. Thank for the info man.

Dude you stole my avatar that's not cool bro

I've had this Avatar for hella years man! lol I got a sick image ima change it now

mixing ffof and happy frog might be a good idea. the soils have fert in them already. adding more is your problem. it's not a good idea.