you got ph troubles...check run off and water for ph level adjust it. Cheers
14 pages and just seedlings...really wont wait for a joint from here.
PH could definitely be a factor, however don't you think that this early on the cotyledons should be providing everything the plant needs regardless of water PH? It shouldn't quite be at the stage yet where it's having to leech nutrients from the soil, which is really when PH comes into play, but someone correct me if I'm wrong.
My guess is still over watering, cause I've experienced this exact same thing before.