On-site, on-demand generation of MIOX (mixed oxidant disinfecting solution) provides several advantages for the cooling tower industry. These include excellent control of microbial populations even at the elevated pH typical of cooling tower waters, no negative impact on traditional scale and corrosion inhibitors, and environmentally friendly operating conditions. As an inherently safe technology, it only uses common sodium chloride salt as a feed stock. The solution can be fed directly to the cooling tower and controlled via ORP (Oxidation Reduction Potential). Operational sites have demonstrated significant reductions in operational costs when compared to conventional bromine or chlorine chemicals.