Stage...lots of good Q's. Spray Brix every 7-10 days , concentrating on getting a fine mist to the undersides of the leaves(better absorption ). Doesn't really matter when , in the cycle...just don't overdo it. I like to spray on "off" water days. With DeStress , any time your training , transplanting, SC'ing, switching lighting sources from flour. to LED, or any other form of stress use this spray ....if they are not hurting or under any stress, save the spray for when they really need it.
It looks like you have one on the left there that has really droopy leaves...what's up with that one? As far as what to give them next....I would give them a Drench with GE and a splash of tea. Remember Stage...don't feel compelled to always give them something. Alternate the Drenches with two plain watering's between them OK. With this system , it's totally fine to give just water between drenches...you don't always have to give them 1/4 Trans....they will do great without it! Sometimes it gets boring using Doc's gear , but that's a good thing , cuz we're all a lil less stressed when we're not trying to figure out what went wrong....