Where did the side branches go...?
What are you using for lighting, and did you let it get too close to those burned leaves? (CFL burn?)
You can usually call an aquarium store close to your house, and ask what local water ph is. This should give you a pretty good idea idea on which direction your water needs to be nudged. (if any) A ph test kit or ph pen is virtually mandatory, but each has it's limitations.
If the water smells like chlorine, let it sit out overnight to evaporate the gas. (chlorine is a gas) If it doesn't smell like chlorine, definatelly not a chlorine poisoning issue.
Those occational spots on leaves can be from a number of things from bugs to nutrient splashes. Might even be something simple like from a neighboring leaf irritating 'em.
What brand of nutrients are you using with every other watering? Most nutrients are a once a week thing. Unless you know how to adjust to keep the weekly totals in line with manufacturers recommendation, should likely follow directions to a tee.

A few minor issues, but overall pertty nice. :thumbsup: