Strategies of attack on patio-brick fungus

Q. How can I get rid of moss or fungus on patio bricks? Previous chemical solutions have been of only temporary help. Neither weed killer nor salt have helped. Carol M. LeClair Falls Church, Va.

A. At least two companies now offer moss removers. Ask for them at your local paint or hardware store under the names of Dowicide-G by Dow Chemical Company and a product by Sherwin Williams. There are others as well. Follow the labeled directions.

If you want to make your own fungicide, mix mineral spirits with 10 percent pentachlorophenol (penta). Apply it in liberal quantities to the mossy brick and scrub. Rinse thoroughly, being careful to keep the solution away from vegetation.

Another homemade remedy is to blend one gallon warm water, one cup household bleach, and one-half cup of nonammonia liquid detergent. Scrub the brick with a stiff- bristle brush. Rinse. Keep it all away from vegetation.

Whatever you can do to keep the brick dry or out of the shade will help to prevent return of the moss.

Fungus is persistent so don't be surprised if per iodic applications are required.