Based on your pictures, I'd get at least one, maybe even two more fixtures. The primary sign that a seedling isn't getting enough light is the way that the outer seedlings are 'reaching' towards the light. The very long stem is weak, and may not be able to support the plant as it gets larger.

I have a setup similar to yours, and I never put more than three flats, lengthwise, beneath them.

Good luck with your project. It looks like you're gonna need the whole family when it comes time to plant everything outside. ;)

1. double your lights.
2. rotate your seedlings.
3. Use cool white bulbs.

dcarch

Yes, the seedlings are asking for more light. Drop the temperature (might need a fan) or increase the light. Your lamps appear to be sending a high proportion of their light out to the sides, you should add further reflectors or shields further down at the sides.