Flipping to Flower Today

You guys helped me get through my first rough patch a few weeks ago (https://www.reddit.com/r/Hydroponics/s/xlkwx0d3JE ) I’m flipping my plants to flower schedule today in my first grow. Any advice from the community is appreciated. I’ve got some basics from Google like increase nutes and light but looking for some advice with some experience attached. My structure is an NFT system and my water is at 6.1 pH and 1.6EC today. The yellowing on top of the canopy has started to turn green again after I added calmag to the res two days ago.

I need to leave town in 3 weeks for a 3 week stretch. Is my grow going to be ok in that time period? Watering and light schedule are automated. What can I do to best make sure my plants are set for success in flowering?

Thanks in advance to this community