autoflower newbie

My name is James. New to growing, but have been growing other crops successfully for about 5 years now.

Good day Autoflower masters. I would greatly appreciate your feedback on my plant, I am a total newbie and need some help with yellowing leaves. It is a Dinafem moby dick auto. 20 days old. I have just got myself a pH pen and have been feeding with plain water pH between 6 - 6.5 . I have also...