Whats up with this plant? Only 1 out of 3 with any probs, grown exactly the same. Pic

Hey, like i said im growing 3 plants. They are all in 5 gal smart pots, roots organic soil under a 400w hps and they get watered with RO water+calmag... and as of last watering a seed light dose of roots organic nutes.

The other 2 plants look perfectly fine...like rly healthy, infact let me go snap a pic or 2 to compare...there. Both plants are 18 days old by the way , im sure u can tell which 1 is the sick one =(

looks a little "overwatered" and deficient of something maybe? the "droopy" look of being overwatered is actually the suffocation of the root system...how dense is that soil and how often do you move those bags around compacting the soil against the root system?

I move them around when i water so i guess about twice a week or so...the soil IS a bit more moist in this pot, i guess that makes sence since its been the runt plant since day 1 and it drinks less.

The thing is i watered a few days ago but i definitely think it looked better yesterday... definitely less droopy and fewer yellow lines on the leaves

Should I give it some micronutes? Maybe a foliar feeding with microblast? I rly don't think it's overwatering, I water it once and let it get pretty dry, like right now the pot it just a little heavier than the 2 others that are pretty dry and need to be watered tonight.

No more opinions? It's not getting better or worse...my other 2 plants are still completely healthy