HELP! Beginner grower, Veg stage

[pv123]

So been having a hard time trying to figure out what’s going on, I had my other two babies die, these two were going good but then they started to curl up and one had that yellow patch not really sure what the grayish color is, been watering it got a PH meter and adding the PH drops, then just added nutrient for the first time yesterday and nothing seems to happen

[SoOrbudgal]

Looks like splash from watering or...........over watered. You gotta give us more about the soil, light and auto or photoperiod. How old and strain. If you have lots of poop or food already perhaps it's burning up the roots. Get a better pic of the whole plant

[pv123]

So for soil I use purple cow organics Indicanja 1, but before we transferred to the bigger pot we used fox farm soil but the bag we got was frozen and then we defrosted but think turned into mold so transferred and used the new soil(don’t think that was the best idea) so might go back to fox farm and stick with that, got photoperiod and strain is zkittles, and the light is vivosun, and they are about 4-5 weeks old, also thinking trying to figure out of how to pull fresh air into the room during the winter time, just need it before it gets 75-80 here and that could take probably 2-3 more months

[SoOrbudgal]

Good morning pv123 i looked up that soil ya know it's got cow feed lot grow medium so it maybe too hot for the seedling. I know it wasn't cheap if it came from " bezos " I've grown Zkittles loved it. I mix soil with coco coir, xtra perlite. Don't be surprised if you get knats from this soil from the cow. I'm not growing photos right now but if i did the only fresh air is open tent while light is on for me. I open vents and parial door. I don't have exaust system never have but i'm attentive to air flow using a fan, i don't care about the smell just moveing air around.
I'm thinking the soil is too hot at this point.

[golfnrl]

Pic number 1 looks a little leggy. How high above the canopy do you have your light? Your plant may be stretching to reach the light. Tell us a bit more about your light.
How do you water? How often? How much? Reason I'm asking is SoOrbudgal mentioned it and it's very easy to over water. Have you heard the phrase, 'love it to death?' With cannabis that's very easy to do. It's more difficult to over water with coco coir, that's the main reason I switched to it.

[pv123]

I haven't watering past day twos, have been watering once a day, and usually check soil dry first inch, but it’s been since we switched the soil, maybe thinking of going back to ffarm

[pv123]

The light is about 2ft, led white light pushing out no heat, 500-600L, moved it up couple days ago, maybe having the humidifier without any heat, winter rn going to spring soon

[LemonBud]

So did you transplant while the ffarms was cold and froze.