I use canna coco and line with ro. Last run I used 5ml a gallon call mag always every watering. I got awful lockout and potassium and mag were locked out. I figured from too much cal? This run I'm using no cal mag and hitting a slight mag def. I hear cannas made for ro then cal mag to 200. Shits killin meMost brands of coco ate shit bcuz they do not properly rinse before selling and it has way too much salt.
If u buy any coco coir besides Canna then test the run off ppm... It should be around 60ppm... But I've seen other big name brands have as much as 2000 ppm, and then they say coco sucks... Wrong.. Buy Canna or test your coco ppm for excess salts.