how old are they, how big are the pots, what stage are they in? all of those questions need an answer. Also are you feeding them and how much?
take a look at my newbie experience blog about watering. I talk about all the troubles I had with seedlings. They are going through transplant shock, for sure. This is where the roots are shocked because of the new environment you just put them in. Growth will normally slow when you transplant because of this. The roots are simply growing themselves better before the plant focuses on foliage. Water them when the soil is more dry than moist, if its drying up fast. You should add some perlite to ur soil. However, this should have been done before the transplant. Perlite helps retain water. Another trick my parents use is putting some broken clay pot pieces in the holes to help retain the water. You could also line the bottom with rocks.They are about 2 1/2 weeks old and i just transplanted into an 8 inch pot. I am going to start fertilizing soon. I have been water feeding them but from everything i've read you shouldn't water everyday, however every day it seems like my soil is totally drying out and i don't want to starve them.
