Copyright (c) 1996, Roanoke Times

DATE: Tuesday, August 6, 1996                TAG: 9608060036
SECTION: EXTRA                    PAGE: 3    EDITION: METRO 
COLUMN: At Home With Technology


Q: Now that we're retired and take longer vacations, I frequently impose on our daughter to take care of our many beautiful house plants. Is there a way to water them automatically?

A: While landscape and lawn sprinkler systems have been around for years, few people realize the same concept taken on a smaller scale can work inside the house. A properly designed interior irrigation system will safely water your house plants while you're home or away.

It is a well-known fact that indoor air pollution poses an even greater health threat than does outdoor pollution. According to Stuart Snyder, an indoor irrigation pioneer, NASA research demonstrates that house plants are highly effective in absorbing and eliminating many air-borne toxins. This research makes a strong case for having a house full of plants. An indoor irrigation system makes this surprisingly easy to achieve.

Distribution lines, made of small plastic tubing, range from 1/4" to 1/2" in diameter. You can install the lines behind the walls during construction, or along baseboard and under carpet in an existing home. One company even sells a unique miniature 'water receptacle,' ideal for behind-the-wall systems. Water is accessed from a hose bib (faucet), a standard plumbing fitting, or a clamp-on tap.

You can select from a variety of water outlets. Drip tubes are great for dense vegetation while small misters are ideal for large planters or patio gardens. Most potted plants, however, require only a simple emitter. You should carefully anchor emitters in the soil or risk watering your furniture instead of your plants.

Emitters are classified according to their flow rate (gallons per hour). An inexpensive pressure regulator will maintain consistent flow rates. If you have unusually long distribution lines or wide variances in height (e.g., multiple floors or hanging baskets), you'll need to use pressure-compensating emitters. At least one company sells an adjustable emitter, making it easy to fine tune flow rates for each plant.

If you only have a few plants or lack convenient access to a water line, a reservoir system may be the best solution. Once you fill the reservoir (small plastic tank), a small pump distributes water to the plants at very low pressure. Inexpensive tubing and snap-together fittings make this type of system a breeze to install and maintain.

Although most irrigation equipment companies offer stand-alone timers, an inexpensive power line carrier (PLC) timer can serve double duty as an all-purpose light and appliance timer. A special PLC relay module designed for switching low voltage loads is an ideal way to control the solenoid valve. For the ultimate in plant care automation, you can use an injector to mix nutrients with the water!

Automatic irrigation systems offer many advantages beyond their obvious convenience. High-frequency watering benefits plants by keeping the soil moist without flooding and by reducing salt build-up. Furthermore, you'll conserve water since evaporation is minimized.

To receive a list of companies that manufacture indoor and patio irrigation systems, please send $2 and a self-addressed envelope to David Butler F-619, Department TWN, P.O. Box 36352, Cincinnati, Ohio 45236-0352. The list includes toll-free phone numbers and a summary of each company's products. You'll also receive sources for PLC timers and controllers.

Q: My house has a 30-year-old low voltage controlled lighting system. I'm curious if it's possible to upgrade to one of the new digital systems.

A: You should at least be able to eliminate the annoying click-clack by replacing your system's mechanical relays with solid state switches. Whether you can add dimmer modules or upgrade your wall stations depends on how your house is wired. A manufacturer's rep can check your wiring for compatibility. (For a list of Electronic Lighting Control Systems, write to the above address and ask for F-541.)

Send questions or comments to Butler at 14713 Pleasant Hill Road, Charlotte, N.C. 28278.

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by CNB