High technology doesn't play favorities. It helps the NASA engineer, the modern architect, the computer programmer and now marijuana dealers. Using the sophisticated techniques of hydroponics, potgrowers are causing new troubles for the Federal Drug Enforcement Agency (DEA), whose agents are unable to find the indoor-grown pot rapidly becoming a lucrative business.

Anyone who has put avocado to water knows the basics of hydroponics, the science of growing plants in soil-free solutions. But plant nutrition specialists have advanced the skill so that large scale commerical operations are now economical. And drug dealers are taking advantage of its use. Hydroponics originated as a purely scientific endeavor when botanists set out to study the needs for survival of different plants. Scientists have now identified the 17 nutrients that must be added to drinking water to produce high yields for plants grown hydroponically. Supplied as soluble salts, these nutrients dissolve in the water at precise concentrations and must be maintained as such to avoid toxicity.

The research paid off during World War II when American soldiers stationed on South Pacific islands with infertile soild used hydroponics to grow vegetables that were irregularly or inadequately supplied. Today, tomato and cucumber farmers take advantage of the method.

But so do marijuana farmers. Over 1000 tons of sensemilla were domestically produced last year, at least 10 per cent of which was produced indoors. With the risk of an outdoor field being spotted by authorities, many growers have moved into abandoned warehouses with low rents. In the biggest raid yet in 1981, DEA agents found $200,000 worth of hydroponic pot in a warehouse just outside of San Fransisco two weeks ago. To their dismay, the crop was not only growing faster than normal, but it contained, according to the DEA, "at least twice as much THC tetrahy-drocannibol--pot's active ingredient) as the best Colombran grass.

The only disadvantage to hydroponics is its high cost. The method is inefficient unless applied in large-scale operations to a high-value crop. The nutrients must be measured precisely, the pH of the water monitored constantly, and the room temperature regulated closely. Most growers accomplish this by a subirrigation system where the hydroponic tank nutrients are mechanically replaced three to four times a day.

More expensive than the nutrients is the electricity needed to run such an outfit. Without natural sunlight, expensive high intensity lamps must be purchased. When the San Fransisco warehouse's electricity bills jumped 1500 per cent the police became suspicious, leading to the DEA's raid on the stash.

Hydroponics remains the agriculture of the future. But if its development continues, the great outdoors will have moved inside.