Q: We have a brick walkway around our house. In shaded areas, it has developed a green-black growth of moss and algae. How can we remove this?
A: Sweep off or scrape off any loose material, then wet the stained areas with a solution of 3/4 -cup chlorine bleach in a gallon of water. Keep the stains wet for 10 or 15 minutes, then scrub with a stiff brush and rinse.
Moss and algae can also be removed from bricks by treating with a weed killer, sold at many home centers and garden-supply stores. Carefully follow directions on the container.
The growth is less likely to return if trees or shrubs are pruned so there is less shade on the bricks. Sealing the bricks with a clear masonry sealer will help keep the bricks from absorbing moisture and possibly retard moss and algae growth.
Q: I have some brass-plated fixtures I want to try to keep from tarnishing. A salesperson recommended waxing them. Is there a better way?
A: Brass is sometimes sprayed with clear lacquer to prevent tarnish and corrosion, but this is a tricky procedure. The brass must be perfectly clean and free of any oils or contaminants or the lacquer will peel. A special spray lacquer called Staybrite is available for about $14 from Constantine, 2050 Eastchester Road, Bronx, N.Y. 10461 (send $1 for a catalog or call  223-8087 to order; Staybrite is item SL-150).
I think coating the brass occasionally with a high-quality automotive wax is a more practical way to help retard tarnish.