Brown Spots turn to Yellow Leaves

My girls have been flowering for almost two weeks now and the fan leaves on the lower part of the plant get small brown spots which then turn all yellow. I've done research and I've come up with Cal/Mag deficiency. If that's the case I don't know how to fix it. I've been following the recipe that came with the technaflora starter kit. Which I'll post at the bottom. I water about every two days depending on the weight of the pot and if I feel moisture when I stick my finger in the pot. I had to move them before I flipped them to 12/12 and they were in a much smaller environment for a few days under a much smaller light and thats when this started. It was just one plant and only a few leaves now the problem is getting a lot worst and spreading to all my plants, so I don't think it's due to stress anymore which is why I'm seeking advice. The new growth looks healthy. Something worth mentioning is that my tent was getting up 90 degrees Fahrenheit for a few days and because it was so hot out where I live. My temps are down now between 80-86.

Here's the technaflora recipe:

B.C. Boost - 3 tsp
B.C. Bloom - 3 tsp
Awesome Blossoms - 1/2 tsp
Thrive Alive B-1 Red - 1/2 tsp
MagiCal - 1/2 tsp
SugarDaddy - 2 1/2 ts
Feed -> Water -> Water -> Feed


The first two pics are of what it looks like in the begining.


These are what it looks like now.


Thanks!!

It looks like manganese deficiency

try to correct pH to 6.0 - 6.5 In hydro, correct pH to 5.5 - 6.0. You are looking to avoid higher pH ranges, as this is where manganese deficiencies are most likely to occur.
Flush your system with clean, pH'd water that contains about half the correct amount of nutrients needed by the plant. Watch to make sure that the problem starts to clear up within a couple of days.

whatever you do don't use molasses, unless you want a slime that will rob all the oxygen from your roots