6 Weeks - Should I Be Worried? Pictures Inside!

My plant is almost 6 weeks old now, and she seems to be doing alright apart from some spots of discoloration. I'm really not sure what's causing it or whether I should be concerned or not.

She's under a 400w MH on a 18/6 light schedule. Growing in Promix HP with extra perlite. Feeding Technaflora's Recipe for Success at 1/2 strength every 3rd watering. Temperatures are constant around 74-75. Runoff Ph is around 6.8. Am I doing something wrong? Any help is appreciated!

looks healthy as can be to me. i did see a spot or 2. i wouldnt worry about it. if it spreads, then worry.

I thinking you could give'em a little more nutrients maybe full or 3/4 doseThey look good but they could use a little more color and with a little more perkinessHeres my videos Part 1 video needs to be fed~part 2 video is after they been fed a full dose enjoyOh yeah I only veg for 4 weeks at the most and I'm grow with 400 watters too~
http://www.youtube.com/watch?v=-nhoUIIWnqY

Well I'm 6 weeks from seed. But I'll probably be putting her into flower soon... I have 2 other plants that are a couple of weeks behind this one though. I guess it won't kill them to be put into early flower though. Thanks for the advice, I'll up the nutes to full strength.