Abstract: Systems for water treatment include a preprocessing stage, an ultraviolet treatment stage, and a filtering stage. The preprocessing stage includes first and second chambers including first and second filter media. The first and second chambers include perforated plates. The first chamber and second chamber are vertically arranged in a filter tower. The ultraviolet treatment stage receives water in a plurality of reactor tanks. Each reactor tank of the plurality includes an inlet, an outlet, crystal sleeve disposed centrally to the interior of the reactor tank, and a UVC light source contained within the crystal sleeve. A controller operates the ultraviolet treatment stage to sequentially fill each reactor tank and sequentially drain each reactor tank and operates a respective UVC light source to emit UVC wavelength radiation within a respective reactor tank while water is in the respective reactor tank.