This paper charts the development of a network-wide harmonic control scheme using an active filter. The individual components required are discussed and developed. By examining the operation of the scheme as a whole, fresh insights are gained into the applicability of previously proposed techniques. The final scheme was shown to systematically reduce harmonic voltage levels across a network to within specified limits, without the need for a priori network impedance information. This work hence demonstrates the feasibility and effectiveness of active filter based network-wide harmonic control.