Yellowing fan leaves. Normal or not?

Outdoor grow. Not sure of the strains, but started from seeds. I've topped them all once or twice, and tied back most of them somewhat to increase budsites. All soil was compost from a pile my brother and I have had for years now. Was using AN Sensi Grow A/B for a while but have weened off and now just use water. Noticed about a week ago the Fan leaves only have started yellowing. Not sure if this is normal or not? Nitrogen deficiency? ANY help would be appreciated. I can get better pics if needed.

 

That's what I was figuring. Should I start again with the nutrients? I have the A/B, and FF GB, FF BB, and FF TB. Was gonna wait till i saw signs of budding, then start the BB, but should I now?