Ugrow Organic: Nutrients

Nutrients provide a plant with the building blocks it needs to function, grow and reproduce. In nature, plants get their nutrient supply from the soil surrounding it. In a soil less hydroponics system the plant relies on a nutrient solution to provide it with a balanced combination of elements, minerals and trace elements it needs.

The nutrient solutions available for conventional gardening often don't contain the vital elements, minerals and trace elements essential to a hydroponics system. These nutrients often sold as 'plant food' or fertilisers may consist of inappropriate levels of elements such as nitrogen and are not as soluble as nutrient products made for hydroponics. Extra money spent on nutrients formulated specifically for hydroponics is money well spent.

Nutrient products formulated for hydroponics come in various forms: single, twin and triple packs. Many of the nutrient pack components when in concentrate do not react well when mixed together in storage. As a consequence many nutrient products are sold in twin or even triple packs as the chemicals involved can be separated from one another until they need to be mixed with water to make the nutrient solution. There are however new 'single' pack products on the market whose components are more stable in containment. However, twin and triple packs are favoured by many professionals.

Achieving a balance pH, the conductivity of the solution and purity of the water used are factors that must be considered when mixing up a hydroponics solution.

Water

Although generally safe to plants, water containing chlorine added to the local water supply can cause a plants leaves to brown at its tips. Dechlorinating water can be achieved by simply allowing the water to stand in a bucket overnight. The chlorine will rise to the surface and dissipate in the atmosphere.

pH

The pH of the diluted nutrient solution should be 6. pH should be checked regularly at least once a week. pH test kits come in either a chemical or electrical form. The chemical test kits are inexpensive and involve taking a small sample of the solution in a test tube and adding a universal solution to it. The pH of the solution is then determined by matching the colour of the solution to a colour chart supplied with the test kit. Electrical pH meters are more expensive but accuracy is better and they are quick to take a reading with. The tip of the meter is dipped into a sample of the nutrient solution and a reading is taken from a digital display on the meter. pH meters require a calibration fluid which adds to their cost of use. For growers who need to take a large number of readings regularly a pH meter is an invaluable, accurate tool.

Conductivity

Testing the conductivity of a solution determines the strength of the nutrient solution. Neutral, distilled water contains no elements or minerals and as such is a poor conductor of electricity. There is a positive relationship between the amount of elements and minerals a solution contains and its conductivity: the greater the number of elements and minerals the higher the conductivity of the solution.