Hydroponics is a system of agriculture that utilizes nutrient-laden water rather than soil for plant nourishment. The re-use of nutrient water supplies makes process-induced eutrophication (excessive plant growth due to overabundant nutrients) and general pollution of land and water unlikely, since runoff in weather-independent facilities is not a concern.
Hydroponic systems do not require pesticides, require less water and space than traditional agricultural systems, and may be stacked (if outfitted with led lighting) in order to limit space use (vertical farming). This makes them optimal for use in cities, where space is particularly limited and populations are high-self-sustaining city-based food systems mean a reduced strain on distant farms, the reduction of habitat intrusions, fewer food miles, and fewer carbon emissions.
The Hydroponic System
Within a hydroponic system, roots of a plant are suspended in either a static, continuously aerated nutrient solution, or within a continuous flow or mist of nutrient solution. This pH adjusted nutrient solution is comprised of 16 of the 19 required elements for survival, some of which include carbon, oxygen, hydrogen, potassium, iron, and copper.
The pH, which measures the acidity or basicity of a given solution, within the hydroponics system is of critical importance to the viability of any plant’s growth. While this pH level will vary for each plant, most plants grow best in a slightly acidic environment, with a pH range between 5.5 - 6.0.
Benefits over Soil for Plant Growth
Simplistic in its model, the hydroponics system offers several advantages over the traditional use of soil for plant growth. The plant is not grown in soil, which provides the ability to control exactly what type of nutrients are entering the plants, allowing workers to immediately correct any possible nutritional deficiencies.
This control over the environmental growth conditions further guarantees the eradication of pests, fungi, and soil-borne plant diseases that are typically found in open systems. The conservative nature of the hydroponics system is further emphasized by its prevention of leaching, a process in which a considerable amount of plant nutrients are lost to the soil following rain or irrigation.
While taking into consideration the cost of construction and the required training to maintain these systems, hydroponics remains one of the most advantageous options for agriculture production to date. The utilization of hydroponics allows for crops to be grown in a protective and sterile environment while producing maximum yields in a timely manner.
While this agricultural approach appears promising, there is a lack of research on hydroponics within the scientific community. This versatile technology has found its applications in industry, agriculture, and government, and may offer future, more capital-intensive solutions to various manufacturing problems.
Hydroponics come up with several obvious benefits that the soils cannot compare to. Let's see.
Better growth rate.
It's not uncommon to see that Hydroponically grown plants than enjoying a 20-30% better rate than those in the soil, grown in the similar conditions
This is because plant roots directly contact with the nutrients rather than searching for food in the soils. All of these energies will be instead consumed in its growth, and in producing fruits and flowers.
Growers are also in charge of the whole growing system - nutrients, temperature, lights, and so on. By this, you can provide with the ideal conditions that plants require.
Hydroponics saves water
It is estimated that agriculture consumes 80% of fresh water in India.
Meanwhile, the FAO predicted that the food production would increase by 70% when the population hugely expands.
That would be a huge issue to deal with for future farming.
It's when Hydroponics is adopted as a viable solution. This soilless growing method uses only 10% water in comparison to soil agriculture. It is able to do that because of its efficient re-circulated system. Hydroponic plants get the sufficient water while the run-off ones are captured and get back to the system.
No soils needed.
This comes with two great benefits:
(1) You can grow crops anywhere whether in arable or heavily contaminated places. It saves the lands by growing plants in convenient locations like large-scale indoor greenhouses, or even in your apartment.
(2) All of the weeds and soil-related pests and disease are eliminated in a Hydroponic system.
Effective use of nutrients
All nutrients are added to the solution, and you are 100% controlling giving the specific amounts of foods (nutrients) that plants need. Unlike the soil, nutrients are not lost because they are held in the reservoir.
Potential Downsides of Hydroponics
Upon starting, you are sure to make some investments to get necessary equipment for the system, including a hydroponic air pump, timer, lights, air filters, fans, containers, growing media, nutrients, and etc.
Technical knowledge and experiences.
Depending on the scale and types of your systems, you'll need to own specific knowledge to set up, maintain and monitor. You'll also need to know how plants work in Hydroponics. Don't worry about these issues, because we are here to do that for you.
System failure and power outage.
The plants are depending on you for their survival. In case a power outage happens, they face a great risk of death in a few hours when the plant roots are stopped watering and get dried.
Type of Hydroponic System
Nutrient Film Technique (NFT)
NFT works by continuously flowing nutrient solutions onto the grow tray, so it doesn't need a timer. The solutions then run through the roots system of the plants till its reaches the channels' end then drains back to the reservoir. It is able to do that because the tube is slightly downward. NFT does not need any growing medium.
What Makes a Good Growing Medium
There are limitless growing media around us. Even the air can be a great material as long as it can provide plant roots with oxygen, moisture, and nutrients.
When choosing a growing medium for your Hydroponic system, these are the great traits that you should take into account:
Good aeration and drainage - does your medium hold the moisture and oxygen well?
Lightweight enough to work with and carry around.
Organic made and environmentally friendly.
Let's go over some of the most popular media used in Hydroponics.
Common Types of Growing Media Used
Coconut Coir, or also called "Coco-tek", "Cocopeat", and "Ultrapeat" is an organic material created from the coconut shell husks.
The byproduct of the coconut industry now becomes one of the widely used media for Hydroponics.
That is because of several advantages listed below.
Able to hold water and the air well.
Renewable & environmentally friendly
Do not have good drainage. So often mix with other material.
Uncompressed after several uses.
Perlite has been widely used to add aeration to the soil by traditional gardeners for so long.
But this material is also one of the common medium choices in Hydroponics as well. It is created by expanding volcanic glass under extremely high temperature. Consequently, countless small white particles pop out like popcorn.
High oxygen retention
Too lightweight for some Hydroponic systems.
Dust from the particles.
Rockwool has been used popularly either by hobbyists for commercial farmers in recent years.
This material is created by melting rocks and spinning them into bundles of filament fibers.
Rockwool is a versatile inert growing medium which can be used as a standalone material and many types of Hydroponics system, especially re-circulating types.
Hold water very well.
Good oxygen retention.
Has a variety of sizes and shapes
Not environmentally friendly - Rockwool is almost not able to dispose of.
Dust from the particles.
Not pH neutral.
Expanded Clay Pellets (LECA)
Expanded clay pellets are small marble shaped balls created by heating the clays until it expands into small round pellets.
Great oxygen retention.
Poor water retention capacity.
The porous rocks created from recycled glass is a versatile medium that can fit almost all hydroponic system.
Great air to water ratio
Potential damage to some plant root types because of its clinging.
Hard to clean.
Like Perlite, it's a mined material that is made from expanded pebbles under extreme heat. It is often used in combination with perlite because of its poor drainage capacity.
Great moisture and nutrient retention capacity.
Retain too much water.
Starter plugs are made from organic materials like peat moss and other bio-adhesive matters. This material is perfect for seed germination and plant propagation. It's very easy to transplant to a hydroponic system.
Great for seedlings, and propagation phase.
Usually organic, sustainable.
Only used for seedlings or cloning.
What Plants Need
To survive and grow, plants need:
Plants get oxygen and carbon dioxide from the environment for respiration.
Lights supply plants with energy, which is used in the photosynthesis process to make foods. They get lights from the natural lights of the sun or artificial lights from grow bulbs.
Water gives plants moisture.
Nutrients in the water are what the soilless growers are in total control to let plants reach their full potential growth. They are what we are going to discuss.
As the name implies, Macronutrients are the ones that plants need in large amounts.
Nitrogen is the primary food for plant growth, especially the vegetative growth phase. No nitrogen, no leaves produced. Essentially, it plays the vital role in:
Leaf and stem growth. And its colors and sizes.
Chlorophyll, amino acids, co-enzymes and protein synthesis
Phosphorus is vital for photosynthesis and is one of the components of DNA, the genetic memory unit of plants, which is involved in seed production and plant vigor. Plants require Phosphorus in large amounts at the early phase of seedling, germination and flowering stage. So it is responsible for the formation of:
Potassium is used in all stages of plant growth. It helps synthesize sugar, starches, and carbohydrates. It also plays a certain role in the development of roots, stems, and flowers. Plants with sufficient Potassium have good resistance to bacteria and insects.
Fast-growing flowers and vegetables need Ca nearly as much as macronutrients. It is necessary for cell formation and development.
Again, fast-growing plants also need Mg in large amounts. Mg is essential to chlorophyll production. It helps create the oxygen through photosynthesis and is recognizable in healthy and vigorous plants.
Sulfur the components of 21 amino acid that form protein, many hormones, and vitamins, including vitamin B.
Micronutrients are required in smaller amounts. Yet, they still play an important role in plant growth.
Zincs work other elements to form chlorophyll. Important for stem growth, and vital catalyst for most plants' enzymes.
MN aids in nitrogen utilization along with iron in the production of chlorophyll.
Needed for chlorophyll synthesis and is important to the enzyme system.
Combined with Calcium in forming cell membranes, and chlorophyll
How does pH affect nutrient availability?
The chart shows vital plant nutrients and the levels of pH to which plants can take up the nutrients.
As you can see, not all nutrients are available at the same pH level. Normally, macronutrients (N, P, K) are soluble in the middle of the lines. Meanwhile, micronutrients (trace elements) are available mostly in the pH middle level, and some are at the lower left end of the pH level.
You will notice that there is a sweet spot. That is a little left of the pH chart, namely from 5.5 to 6.5. So the good rule of thumb for plants to absorb necessary nutrients is to keep your solution at the above level
Why Do Plants Need Lights?
For survival, plants need foods. However, they don't actively seek the foods like the human. Instead, they use sunlight to make food (sugars) through a process called photosynthesis.
Plants store the sunlight's energy in a green pigment of their leaves, called chlorophyll.
This can be explained by the reaction:
Carbon dioxide + water + (light energy) --> glucose + oxygen
CO2 in the environment react with water from plants roots under the sunlight. The sugar (food), glucose is created in the process of photosynthesis. Then it is used for respiration or converted into starch and stored.
Types of Grow Lights
When it comes to grow lights, there are a large variety of types and sizes. But in the end, they all come down three main categories - High-Intensity Discharge (HID), Fluorescent, and LED
This perhaps the most popular choice for home gardeners, largely because of its cost, its acceptable efficiency. There are two types of Fluorescent lights - CFL and Tube-style lights.
CFL (Compact Fluorescent Lights)
CFL lights are the inexpensive twisty bulbs that can be found anywhere near your living. Since they are short and don't produce lots of heat, they can be placed near plants and are great bulbs for small set-ups.
Tube-style Fluorescent lights
There are several kinds, including the T5, T8, T12. Among them, T5 lights are the most used and the most efficient.
They are much wider than CFLs and usually comes with many bulbs arranged paralleled one another in a panel.
HID (High-Intensity Discharge)
HID lights are more efficient than fluorescent ones. They deliver more lights per watt as well more heats. So they tend to get hot fast and need much ventilation.
HPS (High-Pressure Sodium)
High-Pressure sodium bulbs give off more light in the yellow and red range of the spectrum.
So even though they can be used in all growing phase of plants, they are more favored towards the fruiting and flowering plants.
MH (Metal Halide)
MH emits light at the blue range of the spectrum. Hence, it's better suited for the vegetative phase of plants.
CMH (Ceramic Metal Halide )
Ceramic Metal Halide (CMH) lights seem like MH, but it works quite differently and more effectively.
CMH has a much wider light spectrum than MH and HPS. And it has better a life-span than the two.
LED (Light Emitting Diode)
LED lights come later in the indoor gardening world. But it is such an efficient method compared to other lights. They produce much light with little electricity. LEDs are incredibly lightweight. They run cool and usually have built-in cooling out of the box. LEDs are made up of many diode and growers can customize which light wavelength/light colors they need for plants.
Which Plants Are Best Grown In Hydroponics
You can grow anything in Hydroponics provided that you create a proper set-up and supply plants with sufficient nutrient balance. But you should not take that mindset and grow anything you want.
This is because some plants will grow absolutely well in Hydroponics while others do not bring expected yields. At the same time, some plants need you for their special care and installation to survive. Let's go to the list
Vegetables: Lettuce, Spinach, tomatoes, kale
Herbs: Basil, chive, oregano, mint
Fruits: Strawberries, hot peppers
These types of plants are fun to grow, work great in Hydroponics and are not a pain to start with.
What Not To Grow First?
This does not mean that you cannot grow these plant kinds. They are just harder to grow and will require special care. Meanwhile, most of the time, the yields are not as good as in the soils. However, if you want to experiment and find growing the specific plants you want the most enjoyable or if you are experienced growers, don't forget these plants.
Deep Root crops
Some root plants require lots of depth for the root systems. You will need to support the roots, and the media must be large and deep enough for the root to grow. These plants include potatoes, carrots, turnips.
Large plants that require spaces
You should stay away from melons, squash, pumpkins, corn if you lack the spaces for growing. What's more, these plants are heavy, so you need to support them properly. But if you have a large area like a huge greenhouse, the barrier has been lifted.