purple stem / dying leaves

[spook313]

1. Soil or Hydro? growing in soil
2. If hydro what type bubble, ebb and flo, etc.? n/a
3. ferts/nutes used? Soil mix? mericle grow for fert / generic potting soil from home depot
4. Lighting: Florous, HPS, MH, or mix? wattages? 3 fluorescent (24 inch tubes)
5. PH if known? no idea
6. What stage of growth? not sure - i've been growing them for weeks
7. Relative humidity and temp of area if known? no idea
8. Grow area size and ventilation? small bedroom closet
9. Any other measurements that may be useful like PPm, EC, CF, etc.? no idea (what any of that means lol)
10. lighting schedule? 16 hours on / 8 hours off

i just noticed that my stems are turning purple. i'm not sure if this is from the strain or if there's a problem. here's a few pictures...

i've also got another problem: the tips of the leaves are starting to die. this was happening before, but as soon as i transplanted the plants into bigger pots (2 liter bottles), the problem was solved. here's some pictures...

any help would be appreciated.

 

[NewGuy]

I would check your ph level asap, I had the same issues and my ph was high and I had nutrient lockout.

 

[spook313]

ok - i'll get a ph test kit asap and let everyone know the level.