Hydroponics farming is a type of horticulture and a subset of hydroculture, which is a method of growing plants, usually crops, without soil, by using mineral nutrient solutions in an aqueous solvent.

Terrestrial plants may be grown with only their roots exposed to the nutritious liquid, or, in addition, the roots may be physically supported by an inert medium such as pumice, cocopeat, perlite, gravel, or other substrates.

Despite inert media, roots can cause changes of the rhizosphere pH and root exudates can affect the rhizosphere biology.

The nutrients used in hydroponic systems can come from many different sources, including (but not limited to) fish excrement, duck manure, purchased chemical fertilizers, or artificial nutrient solutions.

Plants commonly grown hydroponically, on inert media, include

  • tomatoes,
  • peppers,
  • cucumbers,
  • strawberries,
  • lettuces,
  • marijuana, and
  • model plants like Arabidopsis thaliana

Advantages

Hydroponics offers many advantages, one of them being a decrease in water usage for agriculture.

To grow 1 kilogram (2.2 lb) of tomatoes using intensive farming or open field farming methods requires 400 liters (88 imp gal; 110 U.S. gal) of water; using hydroponics, 70 liters (15 imp gal; 18 U.S. gal); and only 20 liters (4.4 imp gal; 5.3 U.S. gal) using aeroponics.

Since it takes much less water to grow produce, it could be possible in the future for providers in harsh environments with little accessible water to grow their own food.

Preparation

To grow crops by use of hydroponic farming you will need to carefully prepare the required items to ensure the optimal growth environment needed.

The materials you will need to include

  • 60 liters bucket
  • 20 liters jerry can
  • Spade
  • Strainer (pest net)
  • Polyvinyl sheet
  • Clean water
  • Plastic or wooden stirrer

Procedure

  1. Scoop five spadesful of pumice and put in the large bucket.
  2. Add 20 liters of clean water
  3. Agitate to ensure the pumice mixes well with water.
  4. By the use of hands squeeze the pumice between your hands to ensure that the calcium carbonate ion dissolves in water.
  5.  Measure the pH of the solution and record
  6. The high pH reading indicates the good quality of pumice as a growth medium
  7. By use of the strainer let the water runoff Add more water once you have poured out all the water and continue rinsing.
  8. Continue washing the pumice with clean water to wash off the calcium carbonate ions
  9. When the water becomes clear, take the pH measurement. It should around 7.2
  10. Add two drops of 68% food-grade nitric acid
  11. Mix and if it is still high, rinse again with clean water until the pH reading is in the range of 5.3 to 6.2
  12. Once you get the right pH range reading put the pumice on the polyvinyl sheet provided. The pumice is now ready to be used as a growth media.

N/B: The nitric acid will react with calcium carbonate ions in pumice to form calcium nitrate that is a fertilizer for plants. No precipitate is formed during the reaction.

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