I know that there's always been a lot of discussion in the OMC on the subject of whether or not coir is nutritious. I contend that it is, after using it on and off, to grow Sandman-style invitro bags.
I also contend that the trick to using coir successfully as a primary substrate is to never leach it. I sort of stumbled upon this observation myself after reading of growers being disappointed with coir's performance in bulk/rez-effect grows. I always scratched my head, thinking, "Why would anyone be disappointed with coir?" But then I realized that many folks were preparing coir by leaching it, as one would in preparing most dung. Hell, if you read most of the coir prep teks online, most of them involve some sort of leaching in the tek.
And I believe that the leaching process removes some of the nutritional value of coir.
Here are some pictures of a current coir-only bag of mine. It's Redboy cubensis strain, grown with 3 quarts of oats spawned to 9 quarts of coir. I expanded one brick of coir with about 3 quarts of water, which seems to come out about right moisture-wise every time. I sterilized the coir in quarts jars for 30 minutes at 15 PSI, colonized the bag on a shelf in my grow room, exposed to regular light cycles from day one. Colonization took about two weeks, and the only air exchange was provided by fans in the room.
This flush amounted to 440 grams wet, which is 44 grams (roughly) dry. I can normally harvest around a quarter pound dry from one of these bags, which isn't bad from a substance that supposedly contains no nutritional value.
Edited by MLBjammer, 19 September 2015 - 08:06 AM.