Hi all the liner is ordered (turns out it was a standard bead) and is (hopefully) being manufactured this week. Another question to you awesome people out there...I have to do some major sanding (and spray painting) to these steel walls and repair/leveling of the sand bottom. How far in advance can I prepare the walls/floor and is there a particular sand I should get for the floor? I anticipate the linier arriving within the next 2 weeks. Thanks for your wonderful and informative site! Kath