Paver stones need to be regularly cleaned and maintained to keep their appearance and add to your property. If you have light mildew on the paver stones, you may be able to wash it away with the garden hose set on a power setting. For medium buildup, use the hose and scrub with a coarse bristled broom to loosen the mildew. For heavier mildew, mix about ¼-cup of bleach with a gallon of warm water, and use a coarse bristled brush to scrub this mixture into the mildew. Rinse very well with clean water.