Understanding Hydroponics and Aquaponics



Sustainable Agriculture – the production of food, fiber and other plant and animal products using farming techniques that protect the environment.  Things, like preventing soil erosion and conserving water, are great examples.

Aquaculture is the process of farming fish, crustaceans, or aquatic plants.  Using tanks, ponds, or even large pens in the ocean, farmers maintain a healthy environment for the fish to grow.  In this example, the fish are raised in a tank that filters out the water, much like a home aquarium but on a larger scale.  The fish are feed, the water is filtered through this filter, and when big enough, the fish are caught for processing.

Fish are among the most efficient in terms of feed conversion.  This chart will represent how many pounds of feed an animal has to eat in order to gain 1 pound of body mass.  Fish only need 1.1 lbs of food to gain one pound of body mass. Chickens require 1.7 lbs of feed, pigs need 2.9 lbs and cows require almost 7 pounds of feed to gain only one pound of body mass.  One of the main reasons fish are super efficiency and feed conversion is because they are endothermic, meaning they do not have to produce their own body heat. Instead, they rely on their environment.  

The next process is hydroponics or the growing of plants in water without the use of soil.  Regular plants grow in the soil where the ground provides both structure and nutrients for the plant.  With hydroponics, plants are supported by varying types of growth media such as clay pebbles, sand or even just sponges.  These types of growth media allow water to flow freely around the plant’s roots to bring nutrients, while also creating a stable structure for the plant.  The nutrients are added to the water via fertilizers and the grower can have precise control of what the nutrients in the water. There is even an offshoot of hydroponics called aeroponics where plants and their roots are suspended in the air. This process provides plenty of oxygen for the plant and it receives the rest of its nutrients from a nutrient solution deliver from a mister.

With a hydroponic system, the water must maintain a steady pH level or a measure of acidity and alkalinity of the water that affects nutrient absorption.  If the pH is too high or too low, the plant won’t be able to absorb the nutrients it needs. If the pH is at a level of 10 for example, there are only small amounts of Nitrogen available, but at that level, there are high levels of sulfur or boron.  The ideal level, where all nutrients are available in good supply is around 7 on the scale.

Hydroponics is also much more efficient than typical row crops.  With a hydroponic system, the water is closed off from the outside environment and won’t be lost due to erosion and only small amounts will be lost due to evaporating.   A large percentage of water for row crops either evaporates or is lost due to erosion. Compared to typical row crops, hydroponics saves 70% more water over the life cycle of the plant.  

The culmination of aquaculture and hydroponics is aquaponics or the process of raising both fish and plants in one system.  The plants are grown in much the same manner as with a hydroponic system except that they receive their nutrients via the water from the fish tank that is full of waste that acts as a natural fertilizer for the plants.  As the fish are fed, they produce waste, that wastewater is then pumped towards the plants where the roots absorb the nutrients and act as a natural filter for the fish, filtering out all the waste and returning fresh, clean water to the tank.  

Most aquaponics systems cost a pretty penny.  But you can buy smaller systems are some stores or make your own for only a few bucks at home.  A simple tank with a Beta fish and a few net pots at the top of the tank can provide you with a great herb garden.

All of this can be of great use to us and the environment.  By the year 2050, the population of the plant will reach over 9 billion people and that’s a lot more mouths to feed.  Sustainable Agriculture, along with methods like aquaculture, hydroponics, and aquaponics, might just be the answer we need to produce enough food and keep the planet healthy.

Thanks so much for stopping by and see you next time!



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