Hydroponics

Conventionally grown plants obtain water, nutrients and oxygen from the soil. Because of the physical characteristics of soil it is likely that one or even all of these essentials is in limited availability to the plant roots. When plants are grown in water i.e, hydroponically, provided the system is set-up correctly the plants have access to an unlimited supply of water, unlimited supplies of oxygen because healthy plant roots growing hydroponically are always in direct contact with the air. It follows that contrary to some expectations the roots of plants grown hydroponically are not usually submerged in water.

SIMPLE OR DIFFICULT?

Hydroponics is really easy. It is often compared to photography where the rank amateur with inexpensive equipment often achieves better results than the enthusiast with all the gadgetry at his disposal.

TYPES OF SYSTEMS

1) PASSIVE. Usually wick systems. They are the easiest to set up because no power is required. In an undemanding situation they can be very effective but the method is inherently less productive than active or powered systems such as the three described below.

2) NFT (which stands for Nutrient Film Technique). Where plants are grown in a continuously recirculating nutrient solution in which no solid medium is employed. It is the most 'pure' hydroponic system and inspire of its name is probably the most simple! The system is very popular, it is economical and highly productive. It is usually used to grow plants which have been raised elsewhere as seedlings.

3) FLOOD AND DRAIN (also known as Ebb & Flood or Ebb & Flow). Here plants are usually supported in an inert medium commonly clay pebbles, perlite or rockwool. Using timing control equipment the cultivation area is periodically flooded and then allowed to drain. In the draining process atmospheric oxygen is drawn in around the roots. Though the system is more expensive than NFT it is aesthetically more pleasing and results suggest more fool proof. Additionally as there are more controls the gadget enthusiast finds this system attractive.

4) SLABS AND DRIPPERS. Here a reservoir of nutrient solution is drip fed, usually to individual plants, which stand in slabs of artificial inert medium such as rockwool or foam. Excess solution supplied through the drippers may be recirculated. The method is not usually as aesthetically pleasing as flood and drain or as simple as NFT, but it is popular in commercial horticulture and it is not short of enthusiasts in the amateur sector.

HYDROPONICS AND INDOOR GROWING
In common with most leisure activities gardening has become increasingly popular. Our climate discourages access to the garden and greenhouse for a considerable time each year. Accordingly fully indoor gardening has become common place. This has been encouraged by the availability of credible lighting systems. It is obvious that in these indoor situations hydroponics is often chosen as the growing method rather than using messy soil or compost.

NUTRIENT FILM TECHNIQUE THE 'GRO-TANK'
The principle behind the Nutrient Film Technique (NFT) is uniquely simple. It involves a shallow film or nutrient solution (nutrient + water) being constantly recirculating past the roots of your plants. Diagram 1 shows nutrient solution being pumped from the tank up to the channel only to flow down the channel (over the plant roots) and back into the tank. It is the recirculating film that differentiates NFT from other hydroponics growing methods.

What then are the advantages of NFT? Firstly yield. It is very much easier to obtain excellent yields in NFT than using traditional methods. It is probable that yield increases are due to a number of factors, among the most important being; a) the plants are always able to obtain the correct nutrients they require b) absence of root disease, typical in soil grown plants c) freedom from the wetting and drying cycle because roots never dry out; and nor is it easy to overwater. d) absolute freedom from weeds e) unlimited supply of oxygen because the roots of healthy plants growing hydroponically are in direct contact with the air. Other advantages of NFT are:

a) the greatly reduced time it will take your plants to reach maturity; b) NFT is very simple to operate (especially the NFT GRO-TANK). You need not be an expert in any skill, gardening or otherwise, to obtain the benefits. c) NFT encourages good root growth

What types of plant can be grown in NFT? There does not seem to be any restraint here, it is common to see plants as diverse as tomatoes, melons, fuchsias, beans etc growing in the same Gro-tank. Plants can be transferred into NFT at any stage as long as there is good root development. Simply place the root ball on the channel.