first grow in coco plant problems help please

im having problems in my coco grow. theyre in 4 gallon autopots but im top feeding right now.

botanicare cocogro with 50% hydrofarm super coarse perlite
using canna coco a+b and botanicare calmag+
temps are 60 in room and 70-75 under lights using 8 bulb t5 ho
ive been feeding EC 1.0 with 1ml of calmag+ per gallon on top of the canna a+b
ph'd to 5.8
when I feed 1.0 ec on my last watering the runoff came out 5.8-5.9 and the runoff EC was 1.2

all the plants are female seeds WW x BB except one which is paradise opium all feminized

here are the pictures, if you need any more information just let me know I need to figure this out I want to start flowering them soon

I know the pictures are kind of shitty but im getting rusting mostly on the more sativa phenos of the ww x bb and on the more indica dominant ones im getting kind of blackish grayish silver spots on the leaves and the one opium plant is kind of having both of those problems

3 waterings ago I gave a 1.0 ec of straight calmag+ and when I water I water until I get a lot of runoff everytime

my tap water is .27 ec and thats included in my final ec reading of 1.0

No offense intended or anything, but I'm currently growing with full coco and coco/perlite with canna products and you're using the wrong base nutrient. Canna coco is really intended to be used with 100% canna brand coco.

For coco/perlite I am using canna substra as well as the canna additives and it does great, no cal/mag needed. And that coco is some pet store brand brick coco.
The difference is canna coco isn't steamed and is treated differently so it releases trace nutrients as the plant needs it and is the reason you don't need separate flowering nutrients.

But this should still be salvagable, the cal/mag is good and expected to be needed, I saw the mag spots on the lower leaves but I'm not sure what's going on with the upper leaves? Is it yellowing between the veins or necrotic?

Do you know what your .27 ec of water is made up of ? Looks like calcium to me.

my coco is botanicare cocogro and its hydrofarm super coarse perlite mixed in..

jarvild said:

Do you know what your .27 ec of water is made up of ? Looks like calcium to me.

Click to expand...

no im not sure what the nutrient value of it is

I used to get iron deficiences early on when I grew in a coco/perlite based supersoil, foliar or top feeding with an iron supplement would green them up. I used botanicare cal/mag+ too which I know has iron but it could be worth a shot. I would just use some stuff I found in my shed that was meant to be hooked up to a hose to spray on bushes lol, it worked though, just gotta dilute and go light.

well i gave them a .8 ec dose of straight calmag+ see if they get better...