Leaves droopy on one, couple others have lower leaves turning dry and yellowish brown

my roomate and i bought some clones approx. 18 days ago. most of them were in small pots and had one slightly larger one that was in a 3/4 gallon. since then i have transplanted all of them except the larger one to 1 gallon pots and all are doing well except for the larger one. they have been outside now for about 8 days and doing great except the larger one is beginning to droop. it is a sour grape strain and unfortunately since i didnt plant i dont know what kind of soil it is. first noticed the droop right before night and read up and seen that that could be normal but now it has a slight droop at all times. i am using fox farm grow big every other time i water (1 tsp/gallon) and dont beleive i am overwatering. also i have been taking them outside at 5am and back inside at nights around 9 pm and slowly winging them from 18/6 cycle to the natural 16 -17 cycle as they will be goin in larger pots in a few weeks to stay outside(the lights are 4 tube flourescent 150 watt). the water i am using is well water(no softeners) with a ph of around 6.8 but have been told it may contain high amounts of iron, could that be an issue of blockin nutes? additionally a couple (3 out of 12) have bagan to turn yellowish brown towards the bottom of the plant but the top maintaining a strong green. anyways heres a IMG_1066.jpgIMG_1065.jpgIMG_1064.jpgIMG_1062.jpgIMG_1060.jpgcouple pics. please help me out and take it easy on me as i am a 1st time grower. thanks

yeah it does. the sour grapes in the 3/4 is the only one that i have no idea. the other ones in the 1 gallon pots are in soil i purchased locally from a guy, it has been used once before but is suppose to be completely organic. i have added some worm casting and kelp meal when 1st transplanted but still am not 100% on what else is in it. tested it with a soil test kit for npk and eveything looked okay