Baja you just need to be picky with which brand of cocopeat you use especialy if using as a peat moss substitute in potting mixes because some have high salt contents. It's best to use what's called buffered or exchanged cocopeat as it tends to be more stable but in small amounts any cocopeat brand will work well for moisture retention and like you said is a renewable resource. I use it sometimes in conjunction with peat moss. I've also used rice hulls as a sub for perlite in the past but both have a little further to come along before it's a cost effective alternative to the more common soil amendments.
