Unknown Problem Please Help

Hi, I have 7 c99 plants that breached the soil almost two weeks ago. A couple are doing ok but many have purple and discolored leaves(light green with purple/grey mixed in). The stems are also purple. All of them are growing very slowly. I'm not sure what is causing this.
Lighting: 4x4' T5 fluorescent light that were about 2"above the top of the plant(1st week) but are now at 4" above tops.
Medium: Miracle Gro Organic, contains slow release nutrients
Water: ph roughly 6.7, I water when the top layer of soil is dry but feel I may have watered too much so I've backed off recently
Air: well cirulated
Any ideas about the strange leaf color or why the growth has become so slow? Is it the MG?
Also I am going out of town Friday and get back tuesday, what should i do before I leave?
I know the photos are low quality, but it's the best I could get. They give a pretty good idea of what the color looks like.
Thanks for the help

miricle grow soil so im gunna go with nutrient burn those little plants require no nutrients once so ever

get those out of the dirt they are n. put them in new dirt with with a alot of perculite vurculite and i used top soil from lowes.. i mixed mine with bone meal blood meal feather meal and bloom blossom a little lime...use no ferts water good and then do not water 4 atleast a week and bam they will return 2 great plants...how do i kno this cause mine done same thing looked good then 1 day. then wilted and turned greyish purple..and mine was also root bound 2...if u dont change dirt death will come

i would say the dirt i use peat free and mix perlite and vermiculite and water about 2 twice a week but i do use nutes ionic for soil grow follow instructions hope that helps

when your plants a re purple, its a sign of less heat. you can stress your buds that way and sell it good people like purple, but it slows your plants down in the process, they dont like it.
i grow in a shed, and winter is comming so i am experiencing the same thing. i sudgest getting a heat lamp for reptiles, or invest in a heating pad, put it around the pot/container or w/e and you should notice some difference

Ok, thanks for the help. I'll get them in new soil ASAP

It turned out to be a nutrient deficieny. I could not get new soil( no car) so I leeched the soil in two of the pots. This made the problem even worse and the plants in these pots never recovered. I added nutrients and the surviving plants began growing again.