I cubic foot of drystall contains a lot of air. -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Gastil Sent: Thursday, July 12, 2012 12:19 PM To: firstname.lastname@example.org Subject: Re: [pbs] Growing medium The Dry Stall website faq says it weighs 28 lbs per cubic foot. Water weighs 1000 kg/m3 which is 62 lbs per cubic foot. So Dry Stall should float on water. Does it? If so, then Dry Stall pumice is more like the pumice I am familiar with, more like Perlite than gravel.