First Coco Grow (Canna Coco). PH: 5,8-6,2 /VPD: 0,9 Have been feeding at 1,3 Ec than was recommended to bump it to 1,5. After the first feeding I got instant tip burn. Lowered to 1,3 again after two days and now it looks deficient again. Nutrient lookout? What should I do?

First coco grow. Calmag problem right? I am feeding with rain water, get the EC to 0,4 with calmag (wasn’t doing that before) and follow the canna coco feeding chart light with ec 1,3 at the moment. VPD 0,8. Is that correct? I would like to start the mainline soon, or would you recommend to wait?