hi, considering getting some of these.....
http://cgi.ebay.co.uk/Aquarium-Inflow-Outflow-Glass-Lily-Filter-Pipe-17mm-L_W0QQitemZ160391102143QQcmdZViewItemQQptZUK_Pet_Supplies_Fish?hash=item25580dfebf
surely, where you attach the tubing to the lilies, the tubing is just going to slide off...