What kind of ntrient should I use ?

I just started my frst time in a garage(two car) I have six plants going with 3 Phillips 1270 lumens lamps and 3 phillips 2270 lumens lamps. I have them all in a line against the wall, seperate 5 and 3 gallons buckets(for there final home) I lightly mist them all 3 times a day, water the soil 2 or 3 times a week(or as needed) I will soon have the wall and area surrounding covered in aluminum foil, for now I have white plastic everywhere. Iam not sure on the duration of my project yet, but I would say 2 months for the oldest one and 2 weeks for the youngest. The oldest is obviously doing the best only minor yellow foliage at the bottom. almost every plant I have I have had to remove a few leaves form the bottom due to yellowing, what could possibly be going wrong or is this normal ? I described my entire set up so if anyone has any suggestions I would appreaciate it. I have pictures but I havent been able to upload them yet, I will have plenty of pics to come. but like I siad any suggestions or advice would be great.

Well, if I were you I wouldn't run the cars in there.

Sounds like a normal lack of nitrogen. Pics would help.

Here are pics for you to look at and see if any of these look like your plants:

Grow Marijuana FAQ, Cannabis cultivation - marijuana growing tips & photos

fox farm nutes are good(grow big, tiger bloom, big bloom)

Everything sounds fine except the misting. Stop the misting and they will perk up. Every time you mist, you dilute the nutrients in the leaves.