Mine is done!!!
I decided on making an ozone reactor.
Firstly ozone is toxic in large quantity and used water should be ran thru carbon, as well as all air escaping from the unit.
My skimmer was happy with the ozone but i had to find a better way to rid myself of the smell.
This is my final work.
Skimmer cup filled with carbon over filter material to plug center hole to rid smell of ozone.
Bottom of skimmer surrounded by carbon bags inside a lees fish breeder plastic container.
Basically water is recirculating and kept in contact for a long time with the ozone/air mixture. (tested this with sand dropped into top of chamber to view some sand again was sucked back up into chamber without carbon bags at bottom)
So now this old skimmer has a new job, and I am happier for it.
If i was to add more water to my sump to raise the water level inside the reactor it would turn into a skimmer again, without the carbon at the top.