I am experiencing what appears to be overwatering and calcium deficency. I am using mother earth coco coir and botanicare cal mag with flora flex nutes. I feed at around 5.8 to 5.9 p.h. i water about twice daily . thia is first time growing indoors. I adjusted p.h. to 6.2 for better calcium uptake wanted to let my plants dry out a little because i was watering to much as i thought u couldnt overwater coco coir.
I supplement the top of my coco with garden gypsum for calcium and epsom salts for magnesium on top of my 5ml per gal of calmag. Coco husk doesn't hold on to the calcium so most plants want more.
I usually add about a cup of garden gypsum per gallon of coir when moistening coco for planting. Then if the petioles start to turn red I add a few tablespoons of epsom salt to the media b4 watering.