hrm. No nutes yet right? You PHing the water? You got proper drainage right? Holes in the bottom of the pot? Gotta ask, some people forget this. Also if you're using tap water, keep in mind there are toxic chemicals in it that have been scientifically proven to cause mental retardation and an IQ reduction in children, if you have high levels of this in your area you might wanna get an RO or water distiller just to be safe. If you have to use that gunk, be sure to let the water sit 24 hrs to get rid of the chlorine.
Ya know those two round things that come up very first on a new sprout? Are those deteriorating on yours? Those were the first to go yellow and dry up when I was overheating my babies.