Fuchs Oxystar oxidation ditch aerators from Kusters Water, division of Kusters Zima Corp., are offered as self-aspirating or blower-assisted, and can be installed in new or existing oxidation ditches. Units are low-maintenance and highly efficient and eliminate surface spray. Replacement of existing brushes or vertical-style aerators is simple and cost-effective. 205/987-8976; www.kusterswater.com.