An improved ridge vent that includes a support, a cover, a housing, and a concealing structure provides ventilation for a building. The housing contains a biocidal source. Rainwater flows down the cover, into the housing, and over the biocidal source. The water treated with the biocidal source then flows out of the housing and down the roof, inhibiting the growth of mold, moss, bacteria, and fungus. The concealing structure hides the biocidal source from view.