Clone problem! First time grower, help plz.

Are the leaves yellow, but the veins remain green. If yes, this sounds like textbook case of MG deficiency. http://www.greenmanspage.com/guides/plant_abuse.html

Check out magnesium. Even if your veins aren't green still consider magnesium.
Remember, foliar feed them. (spray solution on the leaves to be absorbed).

o/
Tieme

 

They might be too hot.

 

Yeah...that could be too. Clones can't take up as much water as a normal plant until they establish their roots so even a little too much heat could dry them out pretty bad.

Good point, doworkson.

o/
Tieme