It depends on the units of measurement being used. Coco isn't presented here (for reasons that I think would be obvious), but it demonstrates how the CEC of any particular material changes, based upon whether or not it's being measured by weight, or volume. You gotta pay attention to the units...That has to be a typo on the peat moss, most sites I've seen show between 100-200 so maybe they meant to put 150 instead of 15?
Truly bizarre, because everything I've read says peat has double CEC as coco and I found more than one site to confirm that as truth. Plus, the amount of people that use peat instead of coco for this exact purpose.
Even more bizarre, some of the links I found say coco has more than peat. So either some people are testing wrong, or there are some other factors at play here that I'm unable to find.
Links below for anyone interested.
link 1
link 2
link 3
Truly bizarre indeed. Until proven otherwise, I'll continue to use peat moss.
But the literal second that someone can conclusively prove that coco has better CEC than peat moss I'm going to switch back.
It took me years, multiple crops/harvests to get the hang of how hydrophobic peat moss is. Peat moss is like some high maintenance shit, looking for any reason to go hydrophobic on you and the instant you slip up on your watering practices you get dry spots.
Coco on the other hand is literally idiot proof in terms of watering. This is why I recommend coco for people new to soil/living organics, because coco is significantly harder to screw up watering with. Once one gets the hang of organics and how they work, then they can explore peat moss until they get the watering down pat.
What is CEC and Why Is It Important? | PT Growers and Consumers
Gain insight into what CEC is and its role in horticulture: nutrient retention, pH and comparisons between growing media.
www.pthorticulture.com
Ignore the title, as it doesn't really relate to living soil systems...