Looking good so far but you have the beginning of stretch.
Since you are doing a breakaway sheet, and can't move plants around, you'll want to get some sort of lighting that gives good even coverage over the whole sheet.
I recommend a New Wave T5 24" 4-bulb fixture or equivalent, no more than 3" from the plant tops, or a T12 tube shop light with a pair of 40w 'cool white' tubes no more than 2" from plant tops. Otherwise you will get stretch. CFLs will work too but they will be a little harder to arrange over the plants.