Astrologers maintain that an astrological age is a product of the earth's slow precessional rotation and lasts for 2,160 years, on average (26,000-year period of precession / 12 zodiac signs = 2,160 years). There are various methods of calculating the length of an astrological age.
It is necessary to kill the mold spores before applying Kilz to the affected area. Diluted chlorine bleach can effectively kill mold spores. After the mold has been treated with bleach, Kilz can be applied to help prevent future mold infestations and to cover stains left by mold. The process of killing and covering mold may require several days.
Once the Kilz is dry you can apply any type of paint over it without using any other primer. I've always used a flat latex paint for ceilings. Both the primer and the finish paint can be applied using a roller, though you'll need to use a brush to cut in around the edges. My favorite type of roller cover to use is called a Kodawool. It seems to have the best pick up and release of the material.