yan402answered grow question 1mo ago Looks like a mix of early nitrogen and magnesium deficiency, pretty common in coco,especially if guano's your only input. Coco needs faster-available nutrients and usually some Cal-Mag support too.
I’d start feeding a proper bloom nute with a bit of N still in it, plus Cal-Mag, and keep pH around 5.8–6.0. She’s not too far gone yet, you can still turn this around.