October 13, 2020

What happens if you love gardening and growing various kinds of plants, but do not have enough ground surface or horizontal floor area? The concept of vertical farming was developed as a solution to this problem. Imagine the way that tall skyscrapers can be built so sturdily, yet are able to reach up towards the sky while containing so many different rooms across multiple levels, and that will provide you with the basic working principle behind vertical farming. In other words, it is all about cultivating more by stacking multiple layers of planting surfaces.

What Is Vertical Hydroponics?

This basic concept of vertical farming can be easily applied towards what’s known as hydroponics—a way to grow plants without the use of any soil, wherein minerals and other nutrients are provided directly to the roots only via water in a systematic manner and in calculated quantities. 

Hydroponic systems can be grown in a greenhouse using natural light, or more commonly in a vertical system using LED lights, to save space. The latter system is what’s known as Vertical Hydroponics—the setting up of a hydroponic farm, except in a vertical manner. Gravity plays a major role, since the nutrient-rich water is fed from the top of the system and flows down to the bottom, where it is collected.

This practice of soil-free vertical gardening traces its roots all the way back to Ancient history. The Babylonians had a similar idea when they built the Hanging Gardens along the Euphrates River in Babylonia around 600 BC—an Ancient Wonder which had flowers, shrubs, and even trees growing in massive tiered gardens. Other records of hydroponics in ancient times include the floating farms created by the Aztecs around Tenochtitlan in Mexico in the 10th-11th century, as well as the explorer Marco Polo’s writings of the late 13th century, describing similar floating gardens during his travels to China.

Scientific experiments were done to test plant growth using various cultures from water, soil and air were recorded from the year 1600 onwards by various chemists. The long search for the macro-nutrients essential for plant growth without soil culminated around 1860, when two German botanists, Julius von Sachs, and Wilhelm Knop, were able to grow plants by totally immersing their roots in a water solution containing minerals of nitrogen, phosphorus, potassium, magnesium, sulfur, and calcium, and delivered the first standard formula for the specific nutrient solutions dissolved in water to allow the growth of plants in it. This was the origin of “nutriculture”, a word that was changed in 1937 to “hydroponics”—combining two Greek words “Hydro” (water) and “Ponos” (labor).

Studies have shown that vertical hydroponics systems can aid in efficient water savings, up to 90 percent. The closed-loop system prevents runoff into waterways while growing indoors can reduce pests, diseases, and issues related to fickle weather. A vertical hydroponics system is efficient in multiple ways, has various advantages, and can be built, operated, and maintained even at your home.

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How Does a Vertical Hydroponic System Work?

There are two main vertical hydroponic system designs—Vertical Hydroponic Tower and Zig-Zag Vertical Hydroponic System.  Due to their unique dynamics, both of these vertical designs use a closed, constant flow system called the Nutrient Film Technique (NFT), which involves having a constant thin stream of water flowing over the root system of the plants.

Vertical Hydroponic Tower

In a typical vertical hydroponic tower, a tube is connected to a small water reservoir at the bottom, wherein a hydroponic pump will assist in pumping the water to the top. From there, the natural assistance of gravity is used to bring water down in a controlled manner back to the reservoir, the process of which delivers the nutrients to the plant.

You can either use a single tube to deliver water to the top level or connect multiple channels to different layers for optimal delivery of water and nutrients. The plants are placed in net cups, typically angled at 45 degrees, to easily allow the water to flow through the roots.

Zig-Zag Vertical Hydroponic System

Some designs use multiple PVC pipes arranged on a trellis frame at diagonal angles (known as the zig-zag vertical system) instead of creating a vertical tower. The pipes are usually in a compact zig-zag pattern going up. The plants are housed in net cups, placed at regular 90-degree angles.

These systems also use NFT techniques to grow the plants. The water containing essential nutrients is pumped to the top pipe, from where it flows down in a constant stream.

Advantages of Vertical Hydroponics

Space Savings

One huge consideration with vertical hydroponics is optimizing the limited space that you might have. Most gardeners nowadays—professionals or enthusiasts—often suffer from lack of floor space, and so vertical hydroponics has become the preferred choice for urban gardening. Vertical systems are excellent for fitting into corners of rooms or any other small indoor or outdoor spaces where they can be less intrusive while not using up valuable square footage. This has allowed maximum usage of small spaces and made it a viable option for growing crops in city homes, whether against an outdoor patio wall or inside a spare room. Vertical hVertical hydroponics is a godsend for people who don’t have access to much soil or ground space to grow things.

In addition, plant roots in hydroponic systems don’t spread out as much in their search for nutrients compared to growing them in soil, since the roots are suspended directly in nutrient-rich solution. As a result, it is possible to grow crops much closer together, saving space. 

Lack of Soil

Hydroponics is being considered as an innovative alternative approach to the future of agriculture, since by using no soil, you can grow many varieties of produce in most places with very little arable land, dry/arid climates, or where climate change and destructive farming practices are causing soil erosion. Similarly, distant cities, islands or hotels can also grow their own fresh food hydroponically instead of resorting to costly imports. As for coastal places with a scarcity of fresh water, desalination technology is in progress so that people will be able to extract fresh water from the ocean for supplying hydroponic gardens as well as for agriculture in general.

Due to the controlled and soil-free environment, weeds, pests and plant diseases are minimized. As a result, the use of chemical fertilizers, fungicides and pesticides are drastically reduced—a big bonus for health and food safety—while the harvested crops may not even need to be washed in most cases.

Efficiency & Productivity

Hydroponic nutrients are derived from mineral salts, essentially the same as those found in soil, but more readily available. The difference is that the nature of soil-based minerals is slow release, whereas hydroponic minerals are fast release with fast uptake, and therefore result in optimal results & faster growth.

As mentioned earlier, when planted in soil, a plant’s roots spread out in search of nutrients, leading to a much larger root system than a hydroponic setup—wherein the nutrients are delivered directly to the root system in almost surgical quantities. This method ensures that plants receive exactly the right quantity of nutrition at the right times, allowing the plant to spend its energy-producing useful foliage, stems, leaves, and fruit (instead of large root systems). 

Vertical hydroponics, especially indoors, allows for better control of temperature, light, air composition, and pests. This results in maximized crop growth rates, quality and yield, in addition to being able to grow most crops year-round. Indoor vertical hydroponics farms can play an important role in filling the market gap, providing fresh produce in all seasons.

In addition, vertical hydroponics can reduce the overall weight of the upper layers by at least 30% compared to using soil as the growing medium for a vertical system—meaning that you can stack more layers on top of each other than you normally could.

Fresh produce can be made available locally with maximum ease and sold in restaurants and farmers’ markets with minimal transport. This helps reduce greenhouse gas emissions while also reducing nutrient loss and produce damage. 

Low Maintenance

In a properly constructed vertical hydroponics system, the water and nutrients inside the tube stay inside it without any spillage or leakage. Moreover, the water keeps getting recycled (in a closed-loop system) until it reaches the point of no use. This ensures optimal usage and minimal wastage. Hydroponic systems are therefore good for the environment since the water is not being evaporated as readily or absorbed into the ground quickly while being recirculated, compared to a soil-based system. In fact, a recirculating hydroponic system can conserve up to 80% water and use up to 10 times less water compared to a standard garden bed. This offers a huge—and sustainable—advantage when water shortage is of great concern, especially since field-based agriculture is one of the greatest consumers of freshwater sources (up to 80% of ground and surface water in the U.S. itself).

Disadvantages of Vertical Hydroponics

Water Flow

The main challenge in a vertical hydroponics system is to deliver adequate water, nutrients, and light to plants on all the levels. Since the plants are placed one above the other, water needs to be delivered in a vertical form, and in order to send the water all the way to the top against the force of gravity, pumps with higher power are required. And if the water is not constantly being sent up, it will pool at the bottom and too much of it will pose a danger of drowning the lower plants.

 Lighting

Lighting in a vertical hydroponic system is extremely important. For outdoor systems, the issue of lighting is not as complicated, as it can be tackled by strategically arranging the net cups containing the plants so that they get better access to sunlight as needed. But if the vertical hydroponic garden is indoors, the plants will have reduced or no access to the sun. You’ll therefore need to invest in electric grow lights to allow the system to flourish. For large scale hydroponic farms especially, the lights used to grow plants constitute a big part of the cost. However, with the advent of new LED lighting technology, growing hydroponic plants indoors is becoming much more economically viable.

All the levels with plants will typically require equal amounts of light at an equal distance, and this can only be achieved by placing separate light panels that cater to the plants equally. For example, peppers require plenty of light for up to 18 hours per day, while also requiring close proximity to light—otherwise they won’t thrive. It’s therefore essential to ensure you’re spending money on high-quality and energy-efficient bulbs for your hydroponic light panels.

In some cases, growers actually train plants to grow horizontally because they want optimal light from above to reach all parts of the plant. Since the plants in a vertical tower system are placed at an angle, the best option might be to use multiple vertically mounted lights to cover all the growing surfaces uniformly.

In the case of an indoor zig-zag vertical hydroponic system also, lighting may be a concern. Panels hanging from the ceiling may not be ideal since all the plants are at different heights. Multiple light panels need to be typically arranged on top of each of the pipes to provide light equally and equidistantly.

The BIOS Solution to Lighting

BIOS® Icarus® Li LED Grow Light bars are a cost-effective solution for vertical farming racking systems (such as vertical hydroponic systems), where multiple bars can be daisy-chained and easily arranged according to desired light bar spacing. BIOS Icarus Li LED is the controlled environment agricultural industry’s choice for a durable, light-weight, and vertical grow light bar. It is a cost-effective solution for a variety of grow light applications where multiple bars can be daisy-chained and easily moved according to desired light bar spacing.

The Icarus Li LED Grow Light has an optimized broad spectrum that maximizes photosynthesis and plant growth, while also providing the ideal conditions for a comfortable visual experience, superior PAR efficacy, and accurate crop assessment. 

• The slim, lightweight design optimizes space and allows repositioning over the plant canopy in a variety of applications.

• Clip or end-cap L brackets allow easy installation into any racking system.

• Bars can be daisy-chained by quick-release connectors toa single power supply.

• LED bars can be installed at various densities to provide PPFD levels up to 1500 μmol/m2-s.

Resource Demand

The production in a vertical hydroponic system is high, but so will be the resources that you utilize for this cultivation. The light panels, the water system, monitoring the water reservoir, etc. will result in increases in invested cost and time. Although setting up a hydroponic system can be done on a budget with minimal costs, the specialist equipment required can be expensive for a commercial scale system.

An understanding of both the technical set-up of the hydroponics system and various plant growth requirements is essential for preventing system failures. Leakages can occur, while different crop types may require vastly different nutrient, temperature and lighting conditions. In addition, the close proximity of water and electric systems poses risk, and therefore careful and regular monitoring of the system is required.

Despite the few challenges and limitations associated with vertical farming with hydroponic systems, it still offers great potential to contribute to a more sustainable future of farming. After the initial setup, the expenses should be limited mainly to electricity and nutrient costs, while the increased plant growth rates and yield often outweigh these added costs.

Light is the single most important variable with respect to plant growth and development and is often the most limiting factor. Therefore, the use of visually comfortable and optimized broad-spectrum LED grow lights such as the BIOS Icarus Li—maximizing photosynthesis and plant growth— is extremely beneficial for plants and growers alike for vertical hydroponic applications