Hydroponics: Pros and Cons of Hydroponic Gardening

Growing plants without soil may sound like a futuristic gardening concept, but hydroponic gardening dates as far back as the 7^th century BC. However, the popularity and mass integration of hydroponics is new. In fact, it’s become so popular, even well-known companies like IKEA and Amazon are selling hydroponic systems to consumers. Many proponents even consider the mass utilization of hydroponics to be the future of farming.

One of the biggest reasons hydroponics has become so popular is because recent studies on hydroponic farming have shown it to have many benefits. Plants grown hydroponically are of exceedingly high quality, occupy less space, and consume fewer resources than traditional growing methods. Additionally, hydroponic growing methods, in combination with vertical gardening, have aided in expanding the possibilities of urban gardening and indoor gardening.

Although the amount of hydroponically grown produce has not overtaken the amount of field-grown produce yet, it is quickly gaining a foothold. This is especially true as more and more consumers are becoming aware of where their food comes from and how it’s grown, as evident in the local growing movement.

What is Hydroponics?

Hydroponics is a method of soilless growing in which the cultivation of plants takes place in an aquatic-based environment. Although the concept of growing plants without soil seems contrary to a plant’s nutritional needs, plants can actually grow exceedingly well in soilless grow systems. To thrive, plants need water and nutrients, which are traditionally absorbed from the soil they are grown in. However, if these nutrients can be provided through a nutrient-rich solution applied directly to a plant’s root zone, plants can be grown without any soil at all.

Hydroponic systems use nutrient solutions to feed plants, and use other substrates to provide support for roots. Additionally, some hydroponic systems require no substrates at all. There are many different methods and variations of hydroponic gardening, ranging from small, in-home systems to large, complex commercial systems.

What is Hydroponic Farming?

_{Hydroponic Vertical Farming System. Source: mustbeyou/Shutterstock}
Simply put, hydroponic farming is the growing of crops on a mass scale using a hydroponic system. Although hydroponic farming isn’t competing with traditional agricultural farming at present, its popularity and potential has not gone unnoticed. Recent technological advances, in combination with social awareness, are bringing hydroponics into the mainstream. As consumers pay more attention to their food sources, hydroponically grown food has a new potential to become a legitimate competitor with conventionally grown crops.

For example, companies like BrightFarms in Philadelphia grow food hydroponically directly on the roofs of supermarkets. This cuts down on transportation costs and takes advantage of available natural light. Then, by selling directly to the markets the produce is grown on top of, their hydroponically grown food can be competitively priced against traditional, field-grown produce. In addition to companies being able to grow better produce competitively, many urban developers see hydroponics as a way to greatly improve the lives of people living in heavily populated areas.

One potential commercial application of hydroponics, particularly in heavily populated urban areas, is vertical farms. Vertical farms implement hydroponics and, instead of growing food horizontally across large amounts of acreage, produce food in vertically stacked layers. In urban areas, where farmland is unavailable, vertical farms can provide a large, consistent amount of food. Additionally, vertical farms, and large hydroponic farms in general, are now being used to provide food for areas that suffer from extreme weather conditions, such as desert or arctic areas.

How Does a Hydroponic System Work?

Although there are many different types of hydroponic systems, they all work using the same basic methods. First and foremost, hydroponic growing systems allow plant roots to come into direct contact with nutrients and oxygen, which are both essential to plant growth, without using soil. Instead of soil, some hydroponic systems use different types of growing media, like stonewool, clay pebbles, coco coir, vermiculite or perlite to provide support for a plant’s roots. In other hydroponic systems, like those that incorporate aeroponics, no growing media is required at all.

As for plant nutrients, these are delivered directly to plant roots through a water-based, nutrient-rich solution. This solution can be applied to the roots using several different methods. Some of these methods include, but are not limited to, the roots being suspended in the nutrient solution, such as the deep water culture method, or the roots can be misted with the nutrient solution, which is used in aeroponics, a.k.a. fogponics or mistponics.

However, ample nutrients and oxygen are not the only elements that play an essential role in plant growth. Light, along with nutrients and oxygen, must be available for plants to absorb, as it is a critical component in photosynthesis. Much like the nutrient solution, proper amounts of light can be delivered to plants grown hydroponically in a few different ways. Some hydroponic systems are open, relying on natural lighting, while other systems rely on artificial lighting to provide plants with adequate amounts of light.

Read also:

• The Dutch Bucket Hydro System and How it Works
• 5 Ways to Grow Your Weed Hydroponically
• 5 Key Things Newbie Hydroponic Growers Tend to Overlook

What is Hydroponics Used For?

Hydroponics is quickly gaining popularity in places where traditional farming simply isn’t an option. In large cities there is little to no access to agriculturally viable land. However, hydroponics serves as a solution to the problem of limited growing space. Hydroponics solves this problem because it can be implemented anywhere. This not only applies to large-scale, commercial farms, but small household gardens as well.

The combination of hydroponics and vertical farms has given many large cities the opportunity to have access to fresh locally grown produce. This is why in many large cities hydroponic farmers are buying up unused building spaces of all shapes and sizes and using them as vertical-farm building spaces. In large cities, vertical farms have been built in spaces such as empty warehouses and old shipping containers. Many believe these types of hydroponic farms can have a positive impact on urban communities by providing fresh produce and bolstering local food supplies.

Why is Hydroponics So Popular for Indoor Gardening in Particular?

_{Hydroponic system can grow crops year-round in less time. Source: Panpote/Dreamstime}
Growing plants indoors with hydroponics allows gardeners to create a garden in their home even if they have a limited amount of space. In addition to being able to grow plants in a small amount of space, indoor hydroponic gardening has several benefits. One particularly practical benefit is that hydroponic gardening is much less messier than soil gardening. Additionally, indoor gardens can be a sustainable source of high-quality produce year-round, provided the environmental conditions are kept optimal.

Indoor hydroponic gardens have several other secondary benefits as well. By growing plants indoors, gardeners can control many aspects of the growing environment. This includes the control of plant diseases and pests. Last, but certainly not least, a benefit that may not be often considered, is that plants grown indoors aid in cleaning the air of different toxins and release oxygen back into the surrounding indoor environment.

What are the Advantages of Hydroponics?

One of the most recognized benefits of hydroponics is that foods grown in indoor hydroponic systems are not subject to growing seasons. In fact, food grown this way can be produced year-round in much less time. Not only can crops be grown in every season, the yield in hydroponic farms is double the produce yield of soil-based farms because the growth cycle is constantly restarting. Yield is not only higher, but many hydroponic farmers claim that the quality of hydroponically grown produce is much higher.

Hydroponic farms not only outperform traditional farms in production; they don’t have some of the major disadvantages that come with soil-based farming, particularly in the area of resource consumption. Although hydroponic systems depend on water and water-based solutions to perform properly, they use about one-twentieth of the amount of water used in traditional gardening and farming.

This is because in most hydroponic systems the water is often recycled and reused, limiting the overall amount that is needed. Additionally, hydroponic farms do not produce run-off. In traditional farming, run-off can lead to the degradation of the surrounding environment. However, with hydroponic farms, water can be reused multiple times.

In addition to using much less water, hydroponic farms do not require the same amount of upkeep that traditional farms do. For example, hydroponic systems do not always require pesticides because hydroponic plants are grown in controlled environments and therefore are not susceptible to soil-borne diseases, pests, or fungi.

Hydroponic farms also require much less labor than traditional farms because they are in compact spaces, often as waist-high levels. Therefore, harvesting and replanting is much easier with hydroponic systems (no digging or weeding required!), making the overall upkeep of hydroponic systems minimal.

What are the Disadvantages of Hydroponics?

Although the advantages of hydroponic farming greatly outweigh those of traditional farming, the disadvantages have kept hydroponic farming from being implemented on a larger scale. The biggest disadvantage of hydroponic systems is that the initial set-up costs are very high.

Many small, home-based hydroponic systems can be built relatively cheaply, but large-scale farming operations can come with a price tag that runs into millions of dollars. This is because large hydroponic farming systems require much more specialized equipment and technical knowledge than is required in traditional farming.

Large hydroponic farms also require constant supervision and monitoring. The amounts of nutrient solution, lighting, and oxygen that plants receive are carefully monitored by specialists. Additionally, hydroponic farming is susceptible to something traditional acreage farms are not: power outages. In the event of a power outage, plants can dry out and crops can be lost.

Power consumption by large-scale hydroponic farms is also a concern. Many indoor hydroponic farms depend on artificial lighting to provide plants with their light needs instead of relying exclusively on the sun. However, many growers believe that if these disadvantages can be resolved, hydroponic systems could be a very economically viable alternative to traditional farming.

What Types of Plants Can I Grow Using Hydroponics?

_{Young hydroponic tomatoes and tomato plants growing in a modern greenhouse. Source: merrymuuu/Shutterstock}
When it comes to plants that can be grown hydroponically, there are plenty of different options as gardeners can grow almost anything in a hydroponic garden. Vegetables like lettuce, kale, arugula, and chard will grow well in hydroponic systems and are highly recommended for first-time hydroponic gardeners.

In addition to leafy greens, herbs like basil, sage and chives are perfect for small, in-home hydroponic systems. Other plants that can be successfully grown hydroponically are peppers, cucumbers, and tomatoes.

Although many different fruits and melons can be grown hydroponically, plants like strawberries and watermelons require a bit more care and space to successfully grow and thrive.

Additionally, it should be noted that crops like vining plants, corn, and root vegetables are not suited to compact systems because they are not space efficient.

What are the different types of hydroponic systems?

There are six basic types of hydroponic systems. Although all hydroponic systems vary in shape and size, they will generally be one of the six basic types, or a combination (hybrid) of them. These six basic types of systems are wick systems, deep water culture systems, drip systems, aeroponic systems, nutrient film technique systems, and ebb and flow (flood and drain) systems.

Wick System The simplest type of hydroponic system is the wick system. In this passive hydroponic system, nutrients and water are moved to a plant’s root zone by a wick. Plants are suspended in a growing media, such as coconut coir or perlite, and suspended over a reservoir of nutrient solution. One end of the wick is buried under the growing media while the other end hangs down into the nutrient solution. The wick, often made from rope or fiber, soaks up the nutrient solution and delivers it to the plant roots.	Hydroponic wick system. Source: Shutterstock
Deep Water Culture System (DWC) These active systems are simple, easily built, and easily maintained. In DWC systems, plants are held up by a platform and float directly on top of the nutrient solution. Oxygen is then provided through an air pump and air stone, much like one would find in an aquarium. DWC systems, also available as shallow water culture (SWC) systems, are the system of choice for growing lettuce as it is a plant that loves water. Unfortunately, few plants other than lettuce will do well in these types of systems.	Deep water culture system. Source: Shutterstock
Drip System Drip systems are the most widely used hydroponic systems. These systems are similar to wick systems in that the plants are suspended in a growing medium or substrate and are slowly fed a nutrient solution. However, unlike wick systems, drip systems require a timer and a pump submersed in the nutrient solution. The timer turns on the pump, and the nutrient solution is dripped onto the root zone of each plant through a small drip line. Additionally, drip systems offer the option of recycling excess nutrient solution that isn’t absorbed by the plant. This is achieved by allowing any unused nutrient solution to funnel back into the original solution reservoir.	Hydroponic System with plants in expanded clay receiving nutrients through a drip irrigation system. Source: Dallasphotography/Dreamstime
Aeroponic System Aeroponic systems are the most high-tech form of hydroponic gardening. In these systems, roots are suspended in the air over mist nozzles and have their roots misted with a nutrient solution. Plants can be misted in a cycle, or constantly misted with a fine spray. These systems often require much more equipment than other systems and are not recommended for first-time hydroponic gardeners.	View of exposed roots with aeroponic gardening. Source: Shutterstock
Nutrient Film Technique System (NFT) NFT systems are very popular as commercial hydroponic systems. In these systems, plants are grown in long channels that have a nutrient solution constantly running along the bottom of the channel. Once the solution reaches the end of the channel, it is dropped back into a main reservoir and cycled through the system again. Like drip systems and aeroponic systems, NFT systems require pumps and timers to regulate the delivery of the nutrient solution.	Hydroponic NFT System. Source: Shutterstock
Ebb and Flow (Flood and Drain) System Although ebb and flow systems are not quite as popular as other hydroponic systems, they are still very effective. In these systems, plants are grown in a tray filled with a growing medium. The tray is then “flooded” with a nutrient solution. After the tray is flooded, the solution drains back into a reservoir until the next “flooding” cycle. Ebb and flow systems are very versatile and can be implemented with a variety of substrates and growing mediums.	Lettuce roots submerged in a Hydroponic ebb and flow system. Source: Shutterstock

What Are the Key Differences Between Active Hydroponic Systems and Passive Hydroponic Systems?

Generally, hydroponic systems are characterized as active or passive systems. Active systems rely on pumps and other mechanical devices to move nutrient solution to a plant’s roots. These systems are also usually recovery systems in that the nutrient solution used is cycled over and over through the system. Active systems also heavily rely on electricity, and can be problematic in the event of a power outage.

On the other hand, passive systems are often easier to set up and maintain. They have no pumps or moving parts and are best for beginners. In passive systems, nutrient solutions are absorbed by the growing medium and passed through to the plant’s roots. However, one drawback to these types of systems is that they have a tendency to leave a plant’s roots constantly wet, which prohibits the flow of oxygen around the root zone.

What Is the Best Type of Hydroponic System?

There is no single-best hydroponic system. Every system varies as individual growers create systems that best utilizes their own resources and needs. The set-up and complexity of each system depends on several different factors. Some factors that should be taken into account when choosing a hydroponic system is space available, crop choice, and budget. Some hydroponic systems are simple and great for beginners, while others require much more time, knowledge, and resources.

What Type of Equipment and Supplies Are Required for Hydroponics?

_{Young tomato plant under LED grow light. Source: nikkytik/Shutterstock}
As every hydroponic system varies, so too do the supplies needed for each system. The amount of equipment and supplies depends on the size and complexity of each system. However, there are basic supplies that are required for every hydroponic system. First, every hydroponic system, regardless of complexity, requires a water supply, nutrient solution, and a reservoir to contain the solution. Additionally, if the hydroponic systems do not have access to natural sunlight, they will require artificial lighting.

Some systems, like wick systems, ebb and flow systems, and drip systems require grow mediums like coconut coir, rockwool, or clay pebbles. Other systems like NFT, aeroponics, and DWC don’t require grow mediums to support plant roots. Instead, the systems use net pots to suspend a plant’s roots. In addition, all systems but wick systems (depending on the size) require the nutrient solution to be aerated to provide oxygen to the plants. This is achieved with an air pump, tubing, and an air stone.

More complex systems like aeroponic and NFT systems utilize more specialized equipment like pumps and timers. Aeroponic systems require misters, foggers, or spray nozzles that vary based on the needs of the individual grower.

Where Can I Buy the Equipment Need to Start a Hydroponics System?

With the rise in popularity of hydroponic growing, equipment availability has also grown. Several big box stores carry hydroponic equipment, as do smaller, specialized retail shops found around the world. Additionally, there are many resources that can instruct growers how to build their own simple hydroponic systems, like wick systems, using commonly available items. New or beginner growers can also purchase small kits or systems, like countertop or wall-mountable kitchen aeroponic systems, that require little to no knowledge or equipment.

Can Hydroponics Ever Be Considered Organic?

Although hydroponics has many clear advantages and disadvantages when put against soil-based agriculture, there is one hotly debated question that does not have a clear answer: Is hydroponically grown food organic? First, in order for produce to be labeled as organic, it is required to be grown without synthetic chemicals or genetic modification, and meet other standards set by the Agriculture Department. However, it is not clear how to label produce that isn’t grown without soil. This is because many organic farmers contend that soil is an essential part of organic production.

On the other hand, hydroponic farmers contend that if they grow produce without synthetic chemicals and pesticides, just as soil-based organic produce is grown, they should be able to consider and market their produce as organic.

For now, the decision remains up to organic certification inspectors on whether or not hydroponics can be a considered a truly organic form of gardening.