Nice and green. They look very healthy. Are you organic of using nutes? What strain/strains? What kind of bulb do you have in your 400?
I'm using nutes nectar of the gods just soil nutrients. I have bubba blue crack gorilla glue and thin mint. And I have a 400 w MH light bulb
You might wanna go another light for 8 plants the blue spectrum is great for veg with MH but HPS is where the bud is at!