Help diagnosis please

I had this a week ago rusty/yellow starting at tips of oldest growth. Someone online said calmag deficiency cut off effected leaves and feed well no it's back and I joined here for Better information, what am I looking at and how do I fix it?

can you upload a pic in normal light and provide more info about your grow up to this point?

Let me break out my crystal ball again.

duplicate thread

Found a seed in my bag, first grow fox's soil Humboldt secret nutrients LED 600w 3x3x6 tent