Help with nutrient deficiency (pics and time-lapse inculded)

I'm 1.5 weeks into veg and around day 3, I first noticed that the stems turned from green to purple. I also noticed some yellowing / brown spots on the lower leaves. The guy at the Hydroponics store said they look magnesium deficient, so during my nute change, I increased Cal-Mag from 3ml per gallon to 5 ml per gallon.
Current setup:

Aeroponics / NFT system using Aeroflo2 by GH.

Nutrients: House and Garden line using 80% strength, I noticed that in the past, going 100% full strength burned my plants.

Current EC: 1.39, PH controlled between 5.6-5.8

A/C room set to 70F, Humidity = 45-55

I've included a time-lapse video for the past week.

Please tell me what my plants are missing here, Do I need even more Cal-mag? Is there not enough Phosphorus / Potassium? Is there a nitrogen toxicity? I'm still relatively new.

Thanks in advance

Back off the fert heat a little by diluting with water is my only suggestion, down to about 0.8 and see how they respond over the next 5 days. Them plants look to small to cope with 1.3EC...looks like a nice set up!

i agree. they don't need 1.3ec
temps too low at 70
humidity could be higher
let pH range from 5.5 to 6.1 instead