help needed

Hi all, i'm a newbie did post yesterday about the yellow leaves but now have some new pics, livers, 8wk veg, 4th week on fish-guts, last week on bio-grow, bit baffled as plants look quite healthy, any advice ???? [/ATTACH][/ATTACH]

Not enough N the yellow in the leaves are a sign that it is lacking chlorophyl production,A little more N will cure this not to mention it causes the slight curl in the leaf as well.But be careful not to give to much N