Well, this is what I think of this situation.

From my knowledge, white leaves mean iron deficiency within the plant because iron is critical for clorophyl production and photosynthesis. I also see that you are using CNS17 Bloom, which tells me that there is iron in your soil. From this, I can guess that there could be 3 things wrong:

1.) Is your pH out of wack?
2.) Are you root bound yet? (I saw your pots and I couldn't tell if they were large enough for the size of your plant)
3.) Iron competes with Zinc and Copper for availability to the plant so, if you have more of these than neccessary, iron may be getting pushed aside.

Check on the first two before checking on the last one!!

Also, you should probably get a second opinion on this because I am in no way a professional. I just work in a greenhouse and read a lot!

SMG