David Pilling pbs@pilling.demon.co.uk
Wed, 03 Jul 2013 04:03:17 PDT

More fine material will make the medium more water retentive - the laws 
of Physics can't be avoided.

How water retentive a medium is, can be measured by a simple experiment, 
see the PBS wiki page:


Instead of words, which mean different things to people, it would be 
possible to quote numbers for the ideal medium for species.

David Pilling
email: david@pilling.demon.co.uk
   web: http://www.davidpilling.net/

More information about the pbs mailing list