yellowing on top leaves, week 4

[Southernherb]

im starting to see yellowing in the top leaves

plants are in week 4, getting ready to flush soon.

planted in pure FF ocean forest, mixed with 30% perlite. Is it possible that this is a nitrogen deficiency?

Could it be light bleaching?

 

[Southernherb]

after further review, i believe this could be the start of an iron deficiency. what do yall think?

 

[Vanilla Phoenix]

Do you have a pic of the plant? And it could be the start of Iron def, but since you're in FFOF soil, the only way that could happen is by not pHing your water/nutrient you are feeding it. Are you pHing the water you give it? Are you using any nutes? What lights are you using and how close is the top of the plant?