IBZ- this pic might be the answer to those funky leaves and white 'fuzzy" stuff-->
---> See the blackened tissue with the white fuzz? That's a fungus, likely botrytis that's infected her,... hence the funky symptoms! I see no Ca defc. here, though the advise given about it is solid,... coco has odd CEC characteristics, and a particular penchant for Ca, and to a lesser degree, Mg,... it will hog free ions until sated, then it'll release and bind more freely,... Are you new to coco? there's a lot to learn about this medium, veru different from other soilless mediums and nothing like soil at all!...easily the [HASHTAG]#1[/HASHTAG] issue with new coco growers coming here,..stemming back to treating coco like soil! .... I can't see the white bits you refer to, but I have doubts that you're getting heavy nute salt deposits this early, which looks exactly like frost on the surface, not fuzzy or micro-fiberous (fungal hyphae)....
Pure Neem oil is great for this, and will help boost the plants immue system,... also, start using a SI supplement regularly, for best effect,... several key benefits to it, and it can help raise pH a bit as well, if that's of an advantage to you,...
