Mangel in der vegetativen Phase

You may need to pre treat Coco. I found that Canna Coco was ok but when I switched to plagron I encountered this. You really should run some calmag and a light base nutrient solution through before planting. Coco is high in potassium and sodium which needs rinsing away. The cation exchange also then 'steals' cal ium and magnesium. When growing in Coco calmag is necessary and should be given all way through till after wk 5 when you can clear use. Keep in mind tho that calmag usually always has nitrogen in it. I've seen 0:0:0 but it's usually 2:0:0 up to 6:0:0