Hi charles17.
I've got a suggestion for u how to get loam(powder). A few days ago i tried to buy loampowder here in germany, to design the sandy area of a new antbasin; not in the Antstore-shop.
So i canvass a few shops (buliding centers f.e.) but i didn't got the loam-powder, even not in pet shops.
Then my girlfriend told me that her mother bought some potter's loam a few month bevor witch dried completely because she has forgotten to keep it clammy. So i took the dried loam-block and started making some powder out of it.
To make the powder i took a rasp ( a very abrasive file for working with wood ) and started to make the powder out of the dried loam-block. After doing this i seventh the powder.
I took me approximately one hour and muscle ache in the arm to become 2kg very fine loampowder.
I hope this helps u if u can't buy loam-powder at your place
P.S.:
I have to apologize for my bad english. ^^
Greeting