Coco ppm/EC question

First time using coco, what should ppm be right after it is expanded before you do anything to it or plant anything?

1 Like

I just used pH adjusted tap water to expand my coco. Then I flushed some more water through the pots so I could get most of the fine material out.

Raw coco contains salt, most suppliers triple wash the coco to rinse these salts. I always test a sample and usually around 50-100 TDS :love_you_gesture:

I soaked canna coco bricks for two days in a calmag & 50% Jacks solution - pH of 6.4. Put the coco in fabric pots and let drain for two days. Then added perlite (5 parts coco - 2 parts perlite).
Did a slurry test of the mixture using distilled water

pH 6.9 PPM 70
pH may me iffy given low ppm


The great thing about coco or coco+perlite is that it’s inert. What drains out should be close to what goes in. If it isn’t, you flush until it is.

1 Like

What @beardless said is the best process. Don’t worry about the ppms of the product. But the calmag soak and the addition of perlite is critical.
My process is a little different but achieves the same result.
I expand the bricks in chlorine free water that has calmag in it. I let it soak a couple days in that solution. Then I drain that from the coco, mix in perlite, and finally place it in fabric pots. Then it gets a good long flush from the garden hose. After which I let it set and drain a day or two so the chlorine has time to go away. Last step is to water the pot with Half strength Jacks 321. From there it will set untill the plant is ready to transplant from a solo cup with coco. Usually use coco from a previous grow for starts.


I used to do similar - hydrate then rinse through kitchen sieve with hose. The sieve washes out the dust and fine particles. I like an airy mix. I am on a private well so I don’t have to worry about chlorine. If I don’t do the sieve thing, I hydrate directly in calmag & Jack’s solution.
coco for cannabis has good info on preparing coco. And, as always growweedeasy DOT com has an excellent tutorial

How to Grow Cannabis in Coco Coir

Last updated Dec 03, 2021