nope ceramic rings in top tray.
as for the other 2 trays dont bother with sponge it already has loads of sponge and get some proper media for the other 2 trays.
i dont use filter floss either as it clogs to easily and need changing constantly and if you want to polish the water just use an internal with it in.
fill the trays with bio media and as much as possible.
try and get this its realy cheap but very good.
http://www.evolutionaqua.com/display.php?display_id=19&class_id=19
i get it from here
http://www.paddock-farm.co.uk/productdetail.asp?id1=22&id2=514
they can ship some for you and i bought litres of the stuff for £12.50 but cal them as they do smaller bags.