“…The maintenance/monitoring frequencies reported in the articles we reviewed varied widely. Frequencies were wide ranging with daily (Hanula and others, 2000;Langston and others, 2007;Marnewick and others, 2008;McQuillen and Brewer, 2000;Mills and others, 2005;Pietz and Granfors, 2000;Thompson and Burhans, 2003), every 2-3 days (King and others, 2001;Rogers and others, 2005;Steen, 2009;Stein and others, 2008), once a week (Donaldson, 2007;Larrucea and others, 2007), every two weeks (Grivas and others, 2009;Karhu and Anderson, 2006;O'Brien and others, 2006), and once a month (Song and others, 2008) maintenance reported. Maintenance frequencies seemed tied to the type of technology used.…”