ok here we go all in 1 breath ................
/inhales deeply
1st off ph, IMHO, is to low. needs to be between 5.8 and 6.0
2nd did you soak the RW?? if not rut ro you gonna have ph issuse for a while.
3rd RW has a habit of being a PITA with salt build up. Rapid Rooters allot better.
4th were they rooted?? what kind of nutes you using?? you might be able to start them on 1/4 str to help with lacking N (thats the yellowing).
5th If you have not read all the info you could find on this site pertaining to the type of grow you are doing then you need to do it now because you are already behind.
Oh and what is the temp? humidity? air circulation? what are you using for water and how often? what is the ppm of water? what kind of light (type, wattage and hours on)?
The more info you give the easier and faster peeps around here can figure things out but I believe in 1 area allot ........... READ READ READ and READ somemore!!