When to add Liquid Nutes in a Aerogarden (Hydroponics system)

Hi guys. Kinda new to hydro growing and have a quick question.

When should I add the first packet of liquid nutrients to the Aerogarden?, and should I use the entire packet or just 1/2?

The packets are 5.5ml (Picture below)...trying to prevent any nute burn..my plants are 7 days old, and have formed there 3rd set of leaves.

I can't help with how much as I have never seen them packets before but in my hydro set up I run nutes from day 1

I grow with the AG EXTRA, I usually wait about 3-5 days before adding nutes. I DONT RECOMMEND AEROGARDEN'S NUTE PACKS. They're okay for tomatoes and brussel sprouts but not ideal for our favorite plant. If you have to, they may be okay for veg, but I recommend something better for bloom. Im using XNUTRIENTS with pleasing results.