Deficiency? What is it?

Week 1 of flower
Running coco at 82 degrees F with 62 humidity
Suspecting a deficiency but cannot identify what it is exactly and how to treat it.
Feeding Athena

Research potassium...looks like that...I'm not a coco grower, but check your pH is in the correct range.

Is this just shitty old bottom growth not getting much light? Let's see how new growth looks.

Fertigation frequency probably off.Feed every day to a good runoff, dont let it dry back.