Drooping and color change

Hey all,

New here so bare with me...

Im doing my first grow which consist of 6 plants in my closet. They are about 4 weeks old and about 6-7 inches tall. They are growing in COCOGROW bags. They look pretty healthy for the most part but i am wondering why they have begun to droop a bit. Also a few of the plants leaves are beginning to turn a light yellowish-green color. I only water them about once-twice a day. In the morning and sometimes in the mid evening. This method has been doing fine since the start but maybe they are getting too much water ? If you have any ideas to why they are having these problems i would appreciate it! I want to succeed! haha

Cheers,
-Gak