I use coconut fiber substrate. Thank you for your suggestion, to describe it accurately what is actually being determined, in order to provide physical properties of them materials that these are in use as Substrate.If I reconstitute COCO from Coco-Block, and let the loose substrate re-dry, then it will shrink but almost negligibly.When I put 1 Liter of this dry substrate into a pot, the bottom and drainage holes respectively covered with a net (so no substrate will escape after rinsing) WEIGH it before and after RINSING and DRAINING thorougly, the whole container will become 500 grams heavier. BTW 1 Liter of dry SERAMIS, in the same "experiment" becomes 250 grams heavier. Everybody can (try to) verify the Results for themselves.I am curious whether anybody will obtain conspicuously different results xD ....................................................................................................................................................... > Date: Tue, 30 Oct 2012 07:57:55 -0400 > From: gardenbetter@gmail.com > To: pbs@lists.ibiblio.org > Subject: Re: [pbs] Water retained by various soil ingredients > > I really like this thread!!! > > Mike wrote: > >So I took equal quantities of six potting ingredients, > >weighed each one, soaked it in water for six hours, poured off the excess > >water, and then weighed the ingredient again. This told me how much water > >it retained. Here are the results, with 1 = the amount of water retained > by > >sand. > > Maybe I am misunderstanding. I assumed equal quantities meant by volume. > Water retained was by weight (which is great cause 1ml = ig). Just > checking because obviously same weight of perlite and sand is a huge > difference in volume. > > Is coir (coconut fibre) used in bulb circles? > > Shmuel > Jerusalem Zone 9b > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/