Dean9

Ola amigo tudo bem ? A meu ver, mesmo tu regando todas de igual e com a mesma dose de nutrientes. Pode não ser o mais correto, cada planta tem vida própria e como as pessoas.. Igual irmão :) Mas vejo também pelas fotos do teu cultivo que as plantas tiveram stresse de calor ou falta de humidade. Mas não a problema, a boa noticia e que não tens que te preocupar com isso agora :) Estas mesmo no final do cultivo.. E normal as folhas ficarem com carências na fase final. Aconselho te a regar apenas com agua na fase final.. Já agora parabéns pelo cultivo

In coco you start your feed at 400 ppm if your growing autos and 200 ppm if their photos. Right from the time they sprout. After the first week if you see good growth up your dose by 100 ppm. Do this every week until you reach 800 ppm for photos and 600 ppm if their autos. I would at least be feeing these at 500 ppm if their photos right now 400 if their autos, with a little cal/mg once or twice a week.

Your pH should be between 5.5-6.5 for a coco set up. 1.3 and 2 is is gonna cause lockout which it's doing and the pH swing is causing the necrosis patch

Hello your plant suffering of multiples problems. I can see they have suffered of overfeeding and now you have a nutrient lock out. You have calmag deficience so use epsom salt in spray for a quicker effect. Then measure the ph of the drain when you water your plant and correct it if it needs to. Then give them half dose of nutrients. Hope your plants will recover soon. Good luck. Bye