Just wanted to add that good things come in time. Usually the more time the better it is. Anyways, my opinion:
Just like purplehazin said, they do look alittle crowded, not at their current size, but once they start getting bigger and bushier they will fight upward for the light and that can actually stunt there growth. As they grow make sure you pull them away from one another enough so the leaves are not overlapping. You will need some ventilation to supply them fresh air and this will aslp prevent any mold.
I personally am a fan of vegging under MH(Metal Halide) lamps and then flowering under HPS, although i have been told you can do it, but when I tried it, my plants stretched a lot more then they did under MH. Just an idea. They do make a conversion MH bulb to run on a HPS Ballast FYI. But I will say they look really good and vibrant and good color. But I think you will notice a difference under MH. something to think about.