well i have 12 holes. I usually use all but one (i leave one as an access hole). So i take 11 clones/plants all the way through 12/12 in the same tray until harvest.. I just move the whole pot with plants over to grow box rather then remove plants individually etc.. (that wouldnt be impossible anyhow because the roots get tangled, so there is no way to individually remove pots-thats why i just move all plants while they remain in tubs.). I usually let them get about 8-12 inches tall before i go 12/12 which normally gives me 2-3ft tall plants by the time im done. growth during 12/12 will vary with strain, so dont go by my numbers..If i had more vertical space, i would veg until 20inches, but i dont...
Being that u have 11 plants in a small tray, air stones are a must! (i have about 12ft of air stones in each reservoir. 2x air pumps with 2x hoses per reservoir. I think the air stones are the key to my grow). But with 11 plants in a small box you will end up with roots taking up 50% of your reservoir space. With that said it doesnt hold as much water, so make sure u fill it a lot.. and get air stones airs tones air stones!!
I use a 400wtt mh for vegg. Same cooling concept so the light stay super close to the buds. As you can see there is ZERO heat issues. I really like the cool tubes, altough it will cost over $200 per cool tube once you take into account vent ducting, cool tube, fan etc..