Evening Marco, like I said earlier, I ain't no good with hydro, maybe someone will be on in a minute to help you.
But your young plants look great to me, so I wouldn't think there's much wrong, they make all kinds of sh-t to keep them roots white though.Your doing fine, Marco.
Alltatup will know what to tell you, to get for those roots to keep em clean, an white. Your plants are a real healthy looking green. Nice.