For those interested, Koiboy just posted a link over on Koiphen to his updated home page with info on his modified shower.
http://www.koipondfiltration.com/trickle%20tower.htm There's also detailed info on a DIY rotary drum filter, over my head
Looks like the specific closed sided crates he's using are the RPC-6428, link
http://www.rehrigpacific.com/supply_1.html#
I need 10 crates myself and was thinking about going by Rehrig's headquarters here in Los Angeles to pick some up. Not sure how many are in a pallet, but if there's interest I'd be willing to coordinate. They're collapsible so shipping should be reasonable.