Is this new growth or a nitrogen deficiency

New growth will be lighter colored green then the already established leaves. Also N deficiency start at the bottom working it's way up. To add most toxicitys start at the top. You'll have burnt edges and tips along with yellow leaves and brown spots. At this point you should be watering until runoff, you could always check that to get a ppm count and see if it's out of wack. But they look fine growmie. 🙂