This is a document I wrote/saved because this question arises often. Most media are based on peat or bark/peat and amended with perlite and lime. It would be wrong to think one might simply substitute CHCs for bark or coir for peat without making adjustments and work-arounds to allow for their differences. Even then, my results using coconut products has been poor at best. YMMV

Peat vs. Coir

Sphagnum peat and coir have nearly identical water
retention curves. They both retain about 90-95% of their volume in
water at saturation and release it over approximately the same curve
until they both lock water up so tightly it's unavailable for plant
uptake at about 30-33% saturation. Coir actually has less loft than
sphagnum peat, and therefore, less aeration. Because of this
propensity, coir should be used in mixes at lower %s than peat.
Because of the tendency to compact, in the greenhouse industry, coir
is primarily used in containers in sub-irrigation (bottom-watering)
situations. Many sources produce coir that is high in soluble salts,
so this can also be an issue.

Using coir as the primary component of container
media virtually eliminates lime or dolomitic lime as a possible Ca
source because of coir's high pH (6+). Gypsum should be used as a Ca
source, which eliminates coir's low S content. All coir products are
very high in K, very low in Ca, and have a potentially high Mn
content, which can interfere with the uptake of Fe. Several studies
have also shown that the significant presence of phenolic
allelochemicals in fresh coir can be very problematic for a high % of
plants, causing poor growth and reduced yields.

I haven't tested coir thoroughly, but I have done
some testing of CHCs (coconut husk chips) with some loose controls in
place. After very thoroughly leaching and rinsing the chips, I made a
5:1:1 soil of pine bark:peat:perlite (which I know to be very
productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6
cuttings of snapdragon and 6 cuttings of Coleus (each from the same
plant to help reduce genetic influences) in containers (same
size/shape) of the different soils. I added dolomitic lime to the
bark soil and gypsum to the CHC soil. After the cuttings struck, I
eliminated all but the three strongest in each of the 4 containers. I
watered each container with a weak solution of MG 12-4-8 (this was written before I switched to FP 9-3-6 as my 'go to' fertilizer) with STEM
added at each watering, and watered on an 'as needed basis', not on a
schedule. The only difference in the fertilizer regimen was the fact
that I included a small amount of MgSO4 (Epsom salts) to provide MG
(the dolomitic lime in the bark soil contained the MG, while the
gypsum (CaSO4) in the CHC soil did not. This difference was necessary
because or the high pH of CHCs and coir.) for the CHC soil.

The results were startling. In both cases, the
cuttings grown in the CHC's exhibited < 1/2 the biomass at summers
end as the plants in the bark mix.

I just find it very difficult for a solid case to
be made (besides "It works for me") for the use of coir or
CHC's. They're more expensive and more difficult to use effectively.
The fact that some believe peat is in short supply (no where near
true, btw) is easily offset by the effect of the carbon footprint of
coir in its trek to the US from Sri Lanka or other exotic locales.

Al