Week 3 day 5 little nutrients PH 5.8

Common problem with new growers i find If given 24hrs of light witj auto that's pure horse shit Autos work on DLI. You do need mag. I suggest you get epsom salts. 150ppm added to tap..spray your plants with a mist once a wk until pre flower. You can also add this 2 ur sub. Just make sure ur ph falls in line with ur subs requirements.. Also. Idk if u judt uppoted that 1st one..but rhe others need uppotting. Smaller pots, smaller plants

Your plants look good and appear to be growing at a good rate. If it is a Mg deficiency it's very minor and obviously not affecting the growth of your plant. Don't go chasing waterfalls.

The leaves over all look like mag defficiency. Try increasing your PH to above 6 at least. But the leaves also look droopy so it could be slight overwatering in addition.

Looks like magnesium deficiency. A cal mag would fix that. More information helps as well. What's it growing in for starters. Soil or coco?

Looks like magnesium deficiency and ph is low for soil. Should be more like between 6.2 & 6.5