Trying to become more precise

[americaneagle]

These were some freebies that i received from a friend. So i have no idea what the strain is. I am using soil for media and General Hydroponics for nutes. They sit in a 30 gallon tote with a ten gallon reservoir. For every 2 plants I have 1 360 micro jet sprayer feeding them. As of yesterday I started feeding them three times a day for 15 minutes. Before the adjustments I was feeding every 30 min. I switched feeding cycles because i was thinking that I might be over feeding them. Main reason being #5 in the pic below looks like he is having some issues. My light is a hortilux Blue 1000w mh. Any ideas would be helpful.
PH-6.0
TDS-515ppm

 

[Starkx]

6 small babys like that dont need 1000W just yet, throw a t5 on top of them for the firstweek while they veg a bit... but thats just my opinion.

 

[Budshoteyes]

It's number six that looks bad to me,it's way behind the others. Number five looks to be the best of the bunch!
Did you just recently plant number six?

Could the freebies be mixed strains ?

 

[americaneagle]

Oh yeah i feel what your saying on the light it is a bit over kill lol. Number six was actually a late bloomer I had 8 seeds and 6 came out. But im thinking of putting 6 somewhere else, like maybe back under the T5s. That MH is killer by hortiliux though i love it. Ill post some more pics to display the growth. Thanks guys for the input so far it is always welcome.