Again in straight coco after many years => again headache

[Baloni]

Hi... After few years in rockwool slabs I fight with pH in bloom and overfertilizing, damping roots.. but quality was excellent and I really regret my decision switch to coco slabs from canna.

Coco is a bastard. pH is right all the time but plant are burned or underfed nothing between. Classic regime what I use didnt work, ofc I use coco fertilizer with calmag in it already. 3% Mg
If I let slabs to dry, plants after two days have yellowing from bottom. If I water them everyday, they start to be overwatered and overfed or underfed, its shit show again I cant read plants properly. If I hit few of them with 2.0 EC they bounce but others are overfed.
I have theory in my mind when I grow in rockwool and test PPM with syringe samples. I can grow big plants with only 500ppm 300ppm nutes 200 tap water if you replace the whole nutrient solution fast enough you really dont need push EC much. But COCO is mistery with that high CEC I really cant feed the plants with balanced solution I HATE COCO.

I really dont understand how anybody can grow in straight coco many years ago I use 50/50 perlite/coco and it was waaay better.
I think about using BIO fertilizer but didint know if I have colonized roots with bennies enough.
I think its about CEC and watercontent. pH is stable ofc its coco.

 

[120Octane]

Top dress a tsp of calcitic lime weekly...when you are about to use your mix to up pot toss it into a 5 gallon bucket, dump that mesured amount into a tub and add 1/3 cup of calcitic lime for every physical gallon of the bucket...1/3rd cup X 5...add 2.5 gallons of water to it let it rest 2 days and allow the lime to melt into the coir then use....

 

[OG_Bishop]

you're doing WAY too much dude... pH doesnt matter like you think it does. you cant let coco dry out either... if you DO, when you water it again, you'll need more runoff than usual so you can flush out the built up salts IN the coco.

 

[dramamine]

Top dress a tsp of calcitic lime weekly...when you are about to use your mix to up pot toss it into a 5 gallon bucket, dump that mesured amount into a tub and add 1/3 cup of calcitic lime for every physical gallon of the bucket...1/3rd cup X 5...add 2.5 gallons of water to it let it rest 2 days and allow the lime to melt into the coir then use....

What's the reasoning behind this?

 

[CannaRed]

Best advice I can give is to follow the advice at Cocoforcannabis.com
following their system was the best thing I did to kick up my grow game.
Coco needs to be watered multiple times a day.
Do not let it dry out. Don't even let the top of the coco dry to the point of it changing color.
Every watering is with nutrients added.
I fertigate 5 times a day.

 

[Legalcdn]

I second that website. I am using 90% coco with 10% perlite, DTW, 4 waterings on open ended lines.

i prebuffer even if they claim prebuffered. I use Jacks at 3gr, calnit at 2.75gr, epson at .75gr. I also add fulvic acid (no humic). It's all strain dependent but worked perfect.

how many plants are you growing? Sorry to hear about the issues. Have you checked EC on runoff?