Nitrogen??

Does anyone have an opinion on the proper nitrogen level for vegging?

Every one will have an opinion. You need more nitrogen during vegging than you do during flowering. Fortunately, the folks that manufacture nutrient solutions know this, so if you buy good GROW fertilizers, they will have about the right amount of nitrogen. I found, when I was growing in soil, mixing the nutrients in my ph adjusted water, just before I watered the plants, about every 3 or 4 days, worked well. Since you started these with clones you won't want to veg very long. VV