Hey Manyk Myke, congrats on your grow and nice job so far. I don't know if you are over-lighting, I don't know if that's possible with CFL's as long as they are not close enough to be burning your plants. However, I do know that you could be using more effective light. You have mentioned that you use 65% 2500K and 35% 5000K bulbs in your array. Plants will grow better and healthier in the mid-6000K range at Vegetative stage and better and healthier in the low-mid 2000K range during the Flowering stage. Your lights are obviously working, but you may want to at least switch the ratio while you are Veg'ing them.

I also have read that using your chlorinated tapwater will kill any nutrients that are remaining in your soil, of which there may not be much because you have not repotted since they were small. This could be part of the browning of the leaves, as could nutrient deficiencies. I would do some research into nute deficiencies and see if you can match-up any pictures to your symptoms, as that is the easiest and quickest way to try to diagnose the problem.

What are you using for/in your soil?