Dark spots on leaves?

Dark spots on the lower leaves on one of 3 babes.
Mystery genetics. Just noticed today after leaving to school and coming back.
Looks to me like a calcium issue.
FFHF/FFOF/EWC/Perlite

Transplanted since pic into 5 gallon smart pot with 1/3 OF, 1/3 Perlite, 1/3 Supersoil. Given one watering of phd molasses water.

Root ball and current setup.
2 sativas and 1 indica.

STX.OrganicGuerilla said:

View attachment 3901024 View attachment 3901026
Root ball and current setup.
2 sativas and 1 indica.

Click to expand...

time to uppot

And so I did!
Can I have some opinions on temp.