Hydroponics

Trying Out the Nutrient Film Technique

The nutrient film technique is one kind of so-called solution culture in hydroponics. Solution culture hydroponics involves the growing of plants without soil and without any sort of solid growth medium. Many hydroponics practitioners believe that solution cultures are the only true form of hydroponics. They say that when growers add solid growth mediums, they invariably are adding nutrients to the plants in the same way soil does. The nutrient film technique, on the other hand, like all solution cultures treat the plants only with nutrient solutions mixed by the growers and delivered to the plants via water.

The nutrient film technique used to be common practice among commercial and small scale/amateur/hobbyist hydroponic growers. The technique has fallen out of favor with commercial growers now, simply because new hydroponic techniques exist that are better suited to large-scale farming. Despite the fact that is has now become somewhat antiquated in commercial farming, amateur hydroponic growers and small scale indoor horticulturalists still use nutrient film technique often. It is inexpensive and very easy to use and can easily be adapted to suit many types of plants.

The nutrient film technique works by creating a constant flow of water of the roots of plants, which are suspended in a tub. The water washing over the roots does not flow rapidly, making this technique different from continuous flow solution culture. The water and nutrient mixture is spread out across a flat surface at a depth of approximately 1 to 3 inches, depending on the length of the roots and the depth of the tub. This shallow depth is constantly maintained, and in conjunction with the steady flow of water, creates a ''nutrient film'' over the roots of the plants.

If you want to create your own nutrient film system for plants, you will need a shallow, flat-bottomed tub and a submersion pump. The pump will keep the water flowing over the roots of your plants to help create the nutrient film. The plants should be planted close together. You want to encourage their roots to grow together so the nutrients cling to the roots. Plants the plants so that parts of the roots are out of the water and parts of the roots are in the water. That way, the submersed roots will receive the nutrients and the water and the exposed parts of the roots will receive oxygen for the plants. The submersion pump will pump water into the system and draw it back out, constantly recycling it. Because the water is being constantly recycled, you will need to monitor the nutrient levels in the water closely. You may find you need to top up the nutrients often.

One drawback to the nutrient film technique is that the plants will fail if one component of the system goes wrong. The nutrients you add to the water, while obviously key to the plants survival, actually damage the submersion pumps. If the submersion pump fails, your nutrient film system will fail, and your plants will die. Another danger to the system is electrical failure. If your pump runs on electricity, and there is a power failure, the water will not be circulated through your system, and therefore, your plants will not be getting the nutrients they need to survive. A relatively short disruption of power can lead to complete failure if your plants.

These drawbacks aside, the nutrient film technique remains a viable and useful method of hydroponic growing for small scale and indoor gardeners. By closely monitoring the pumps, growers can make this kind of hydroponics nearly risk free.