ozone generator for water purification

[keron]

hello all,
             please help me with  ideas for generating ozone  and also how to use it in water purification.(say a 500Lit water tank).you will get a lot of circuits to generate ozone but no ideas so far in using it for purification  of water .you will get expensive equipement in market though.
a  bunch of nice ozone generator ideas here
http://www.emanator.demon.co.uk/bigclive/ozone.htm
                                      but what about voltage 5 kv is optimum or u need more volts to get more ozone.
                      is it possible to replace a neon transformer with the  boiler ignition transformer in last project. In that case how to connect the mesh to it .mesh part is not clear i think..