I went to water the girls this morning and noticed these brown spots on some of the leaves! A few days ago I noticed some of the leaves had burnt tips but I thought it was due to my Light height adjustment. 
Growing info: day 75. This is a potforpot grow with an addition of fox farms big bloom and tiger bloom 2tsp each in a gallon of water every other feeding.
Thanks in advance for the help!
Welcome to ILGM!
Looks like calcium deficiency, and I know all nutrients are supposed to be in the soil, but some are hungry than others.
Thanks for the reply! I was thinking that too but I’m a super beginner so I wanted to reach out first before making any decisions.
Have you flushed according to ff trio recommendations
No I did not flush, I began adding the nutes about a month ago.
Have you gave her any Cal-Mag at all?
Just today I ordered some and gave it to the girls tonight.
Give it on water days only
Fortunately, at least for me on first grow, the cal def was easy fix. Used GH CaliMagic. If you water with distilled or RO water, such as I do, def need the cal/mag. The wonderful thing about these plants is that they will tell you right off if there is a problem. And they tend to respond quite well to corrective measures.
Best of luck on your grow!