Hey bud.
Newbie here who spent a grand getting a set up going. Been spending 4-6 ours a day getting my stuff right. Sometimes these guys are crpytic. You'll get used to it. First off, most problems can be answered by googling your question..it'll pull this site with answers, as well as many others. try it.
I can tell you what your problem is. Same thing that happened to me when I tried to use MG or some bark-based soil. It'll start your seed, then about a week into it...it'll burn it all to shit. Leaves start turning yellow, brown..Ive seen it all with my first bag seed plants.
Go get yourself some Jiffy seed starting mix for 4 bucks at walmart. Ive phed it..it's hitting right about 6.8..mix 1/4 perlite in there, from walmart as well. Mix up a small batch, and then RINSE it and let it dry. The run will be a high 7, but the next time it'll be 6.5. I rinse AL my soil and let it dry now. Perlite too. They have the prlite at walmart, has a little nitrogen, but not much. I started with MG, and organic, and unless your water is a 6..it'll burn the shit out of your plants coming out. Hands on experience speaking from last week. I rehabed my NG plant, and he's doing great now since I replanted him...so there is hope.
Your set-up...You need a small 18 inch florescent or 2 from walmart for 9 bucks a piece, shining right on top, bout 1-2 inches away..I just duct taped them to the top of the box(my box was exact to hit the plastic ends to rest on), but cutting holes diaand 2 -3 desk lamps with 100 watt bulbs_the kind that have bendy necks..7 bucks walmart) One will cover each plant, and the flouro tubes from top will keep them growing straight up. TRy to make sure your lights are coming from the top, not the sides.
STart in a 12-14 oz cup..not those big ass planters at first, more nutrients in more soil..more burn...start small..a Dixie cup will keep them in their first 2 weeks of life( I tore many open at each stage to check root development( know whats going on under the dirt).
