AK420 auto

Doin minimal amounts of nutes, just lots of water and sun, this is my first try with a viparspectra 600w LED light, it got 2 switches, one for veg and one for bloom. The Veg switch emits blue light, which is the blue wavelenghts that are supposedly really good for seedlings, and she seems to thrive (: JUN21 update: feeling like something is wrong? like she isn't thriving:( :( ? worried that there's too much Co2 compared to O2 in our tent. We still need a bit of gear so we're gonna have to think out of the box (: JUN23 update: noticing yellowing on the smallest leaf, it seems dead? like it I touch it, it would crumble?? whats going on? feeding schedule consists of 0.5L of nutes dissolved with water ofc and then an additional 0.5L of regular tap water? Please help??