If Iron Bacteria are also present then you will find that the Ozone process will be better or you can, instead, feed chlorine or another disinfectant to oxidize the iron and take care of the bacteria. I prefer multi-media (sand/anthracite) pressure filters over slow sand. In any case, in addition to aeration, ozone or other disinfectants you will need a retention tank to allow sufficient contact time prior to filtration. You may also require a coagulant or flocculant or a combination of those 2 prior to filtration.
Gary Schreiber, CWS VI
The Purolite Co.