Help! First timer and my babies are yellowing after the first week.

I'm currently running a closet grow. I have 12 week - 2 week old girls growing in red solo cups under a lumigrow 650. My medium is Scott's top soil it has some peat moss in it. I mixed 1 part perlite to 3 parts Scott's and 1 part spaghnum peat moss to 5 parts Scott's. I've been watering when the soil is dry which is usually about twice a day. I haven't added any nutrients myself. I'm a first timer and I realize the issue could be cause by several things I was just hoping you guys could help me narrow it down.Attachment 292680 currently only 2 of the 12 are yellowing but I know it's an issue and want to resolve it ASAP

Seedlings don't need fertilizer they don't have any roots to deal with it. The soil looks over watered it only needs to be moist try a spray bottle and fill the cups up to the line so the plant is above the rim it needs to breath and are there drain holes in the cups.

Yes the cups have holes in the bottom.

try this trick next time you plant seeds (or clones!). instead of putting them in straight into the red cup, put them into a clear cup. then slide the clear cup into a red cup - that way the root zone stays protected from the light and you can pull the clear cup out whenever you want to check for how much moisture is in there and how the roots are developing so you'll have a good idea of when it's time to transplant. watering twice a day! try twice a week for the moment!

Ok, I will definitely cut back on the water. If I were to add more soil, is there anything you guys would change? Maybe drop the sphagnum Pete moss? Also is it ok to just fill in the soil sound the stems? I will definitely try the clear cup thing. I'm not sure my medium is right. Maybe it's too light? I'm not sure. I have some 3 gallon plastic pots do you think they would survive a transplant?

Like hoonry say and when you see enough roots then transplant them otherwise the soil will fall away if you add soil to the cups they're in the root will be at the bottom so transplanting to the clear cups for now is you best bet . You need a seedling mix, look on here for one, it is hard to control the moisture in a large pot when the plant has no roots to use it.

Hey guys. I just wanted to say thank you for the help and insight. I'm sure I was over watering. Obviously.. Sucks to suck sometimes lol. I wanted to ask some questions about other mistakes I may be making. Obviously my medium has to change for seedlings. Watering schedule has to change. What about this Lumigrow 650? I purchased 2 of these because a partner and I had bigger plans sadly he got deployed. I bought them because Im not biased on lighting yet and these seem really efficient. 650 watt led with combination 3w & 5w LEDs in the blue and red spectrum. Would the full force of this light damage my girls at this early stage? Or would they love it? I also have 6, 135w ufo lights. ( these arent adjustable ) my girls are sprouting their second set of serated leaves and since I cut back on water they are looking pretty good. I'm actually running 6 different strains right now. One of my Kandy Kushs had a really thin spot in her stalk so I buried her deeper to give support. Otherwise it seems healthy. If you guys have any other suggestions please shoot em my way I would be most grateful :)