zulu54311

Though perhaps not technically a "filter", a UV sterilizer will kill bacteria and other microorganisms. The numbers you provided were for a 50 ppm bleach solution (1/4 cup of bleach per 15 gal tank size) and let sit at least 4 hours. However, you can also use a stronger 100 ppm bleach solution (1/2 cup of bleach per 15 gal tank size) and let sit at least 1 hour.