First Grow

Have noticed some plants have lighter leaves on the younger (top 1/3rd) ones, not sure why. Also I did notice one was showing a yellowish blotchy kind of look on her leaves. I normally feed every water so this water and the next couple I will not “just in case”. This is my first ever grow & I messed up with an extremely cheap blurple light to start with and was also making tent to warm, this has resulted in growth being around 3 week behind I think. 🤔