In the July/August issue of 2001, the article about NFT gullies refers to choosing the “right” gully manufacturer to get the best yielding and most versatile system. Who are some of these manufacturers? I never see ads for NFT gully producers in your magazine or any others I received.
Also, concerning commercial hydro greenhouses, what is the most common source of nutrients? Do most mix their own recipes or do many ready-made mixes from general hydro, Botanicare, or b-cuzz?
I want to add that I really appreciate the work you do at MY. your articles are very helpful and often help inspire new ideas to solve problems in my garden. thanx for your hard work. Sincerely,
Kevin Kennedy
Kevin,
There are a number of companies selling and extruding NFT gullies. Sure Growth in Australia, American Hydroponics in USA, and Rehau in Canada are among the many companies producing and/or selling the gullies. You can also make your own relatively easily. It can be as simple as folding and securing opaque polyethylene sheets or fabricating from PVC pipe round, square, or oval. For best results, make sure that the channel is a large enough diameter to allow for good gas exchange by the roots. Vigorous plants such as tomatoes will quickly fill shallow channels with a dense mat of roots, restricting nutrient flow which can lead to a host of problems. Also, having several points of nutrient solution injection along the length of the channel will help to prevent nutrient and oxygen gradients. A step-up would be a tube-style Aeroponic system. Any system that relies on a continuous flow of a small amount of solution is very susceptible to disaster in the event of a pump failure and to overheating in warmer environments such as those found in indoor gardens. DFT (deep flow technique) uses the principles of NFT, but utilizes a greater depth of nutrient solution via an adjustable overflow to buffer against changes in temperature, pH, TDS, and electrical/pump failures. For economic reasons, many large-scale greenhouse operations mix their own nutrient solutions for their reservoirs, or more commonly proportioner/injector systems. Pre-mixed nutrients are easier to use and offer greater reliability for smaller scale indoor or greenhouse growers. This way, you can focus more on looking after the plants rather than looking after formulas. Hope this helps.