Hydroponics is a farming technique that involves growing plants using only water and chemical nutrients, which means that hydroponic plants don’t use soil for their growth. This increasingly popular farming method is used to grow crops like lettuce, basil, and tomatoes in the US. But what are the advantages and disadvantages of hydroponics?
The benefits of using hydroponics include water conservation, space maximization, predictability, and the potential for higher yields. On the other hand, there are disadvantages like a low return on investment, vulnerability to power outages, and faster spread of pests and diseases.
This article focuses on the merits and demerits of using hydroponics to grow plants. Read on to learn everything you need to know about this innovative farming technique.
How Hydroponics Work
Before we delve into the pros and cons of hydroponics, we need to understand how the method works.
Although plant growth requires many metabolic processes, plants mainly grow because of sunlight, water, and essential nutrients. As a result, some plants can grow and even thrive without soil. This forms the basis for hydroponics farming.
The basic concept of hydroponic farming is to replace the soil with water.
In conventional farms, soil acts as a reservoir for nutrients and water. Conversely, a hydroponic system eliminates it by creating a nutrient-rich aqueous solution straight to the plants’ roots.
So let’s look at the main components of a hydroponics system:
A hydroponic farm can achieve soil-free growing in two main ways:
- Growing the plants in a soil-free medium.
- Suspending the plants directly into the nutritious aqueous solution.
Popular soil-free media include rock wool, coconut coir, vermiculite, and LECA. The inert growing medium supports the plant while anchoring its root structure and retaining nutrients from the aqueous solution.
The plants’ roots can receive nutrients in either passive or active systems. Here are the details:
- Active system: Utilizes pumps to circulate and aerate the solutions. It delivers the nutrients to the plant’s roots for uptake.
- Passive system: Doesn’t have pumps or moving parts. The nutrients are fed into the system using capillary action, flooding, or gravity.
Hydroponics also incorporates supplemental lighting, which mimics sunlight and completes the basic requirements a plant needs to grow.
Since most hydroponic plants are grown indoors, they have little access to direct sunlight. However, the system gets around this by utilizing supplemental lighting.
Hanging electric lights above the plants and controlling their brightness mimics the natural cycles of darkness and daylight required to grow.
Other Components of a Hydroponic System
Submerged plants can die quickly if the water isn’t properly aerated. A hydroponic system avoids this by using airstones.
The stones scatter tiny bubbles carrying oxygen throughout the aqueous solution. However, the airstones don’t produce air themselves and must be connected to an external air pump through a food-grade plastic tube. The tubing also has to be opaque to prevent algae from growing.
Net pots are also common in many hydroponic farms. These pots are made of mesh material that hold hydroponic plants. The nets allow roots to expand from the sides and bottom of the pot, giving them better exposure to nutrients and oxygen. They also provide better drainage than conventional plastic or clay pots.
Types of Hydroponic Systems
The hydroponic farming system also requires a basic system to hold things together. The main types of hydroponic systems primarily differ in how they deliver nutrients and water to plants.
Some systems work with specific plants better than others. Most growers buy the systems as complete units, but others build them from scratch.
The following are the types of hydroponic systems and their unique components:
- Water culture: Uses a floating platform, air hose, airstone, and a non-submersible air pump.
- Wick system: Uses a grow tray, airstone, rope wicks, non-submersible air pump, and air hose.
- Drip system: Utilizes a drip manifold, grow tray, overflow tube, submersible pump, non-submersible air pump, air hose, and airstone.
- Ebb and flow: Uses an overflow tube, grow tray, timer, submersible air pump, and air hose.
- Nutrient film technique: Uses an overflow tube, grow tray, submersible pump, non-submersible air pump, air hose, and air pump.
- Aeroponics: Uses a submersible pump, air hose, mist nozzles, and short cycle timer.
Advantages of Hydroponics
Although it may sound complicated, using the hydroponics system has many benefits. It helps grow healthy plants, especially vegetables, without using excessive space or water and produces a higher quality yield than conventional farming systems.
This farming method also produces vegetables faster than traditional methods.
Let’s take a closer look at these and more advantages of using hydroponics:
Water is the most important resource on our planet. As a result, any farming methods that conserve this precious resource should be received with open arms.
While it might seem counterintuitive, growing plants in water actually requires less water than irrigating them in soil. As a matter of fact, hydroponic plants can use up to 98% less water than conventional growing methods.
This is important because, as of 2019, the World Health Organization reported that only 71% of the world’s population had a safely-managed water drinking service. Furthermore, by 2025, 50% of the world will live in a water-stressed region. As a result, water conservation will be on most sectors’ agendas, including agriculture.
Of the water absorbed by a plant’s roots, only around 0.1% is used by the plant itself. Most of the remainder is released into the air through evapotranspiration. However, with hydroponic systems, plants absorb the water they require and return the rest to the system.
As the global food demand increases, the water strain will only increase. Therefore, hydroponic farming will become more popular as the world focuses on water conservation.
Hydroponics requires less space than traditional farming methods. When combined with vertical farming techniques, hydroponics can use up to 99% less farming area than conventional farming.
The system also encourages higher plant density which means you can grow more crops in the same physical area than in a traditional system.
Additionally, plants don’t have to grow outdoors in the hydroponic system. As a result, the system can easily be incorporated into many homes regardless of their location or size, turning otherwise unproductive spaces into farming areas.
Doesn’t Require Soil
Water isn’t the only endangered natural resource. The world is quickly running out of workable soil. Research shows that the world has lost a considerable portion of its soil to degradation, erosion, loss of soil structure, and salinity in the past century.
Unfortunately, the demand for food is only increasing, which poses a significant risk if we depend on soil for all crop production. Additionally, there’s a considerable soil variation from one location to another. Since some crops prefer certain soil types, they can only be grown in specific areas.
With hydroponics, the soil isn’t a concern. Therefore, farmers can grow whatever plant benefits the local community without checking if the soil is compatible.
Everyone prefers fresh fruits and vegetables. Unfortunately, few people live in an area where they can access these foods fresh all year round due to soils and climatic conditions. With hydroponics, however, soils and seasons don’t matter. As a result, you can grow fruits and vegetables anytime, creating a fresh supply all year round.
In conventional farms, farmers pick fruits before they’re ripe and take them to a warehouse to ripen. Sometimes farmers might even use chemicals to ripen fruits they picked before they were mature enough. Unfortunately, some of these methods are necessary if the traditional farming method is to meet all demand, especially in far-off places.
Food that matures and ripens naturally on the plant typically has more nutrients and is even tastier. Also, since hydroponic gardens have their own microbiomes, these plants can grow just about anywhere at any time. This means they don’t need to be rushed. Moreover, you can pick the fruits at peak ripeness because you don’t have to transport them to far-off places.
Reduction of the Supply Chain
In addition to picking produce before it’s fully ready, traditional farming methods have a long supply chain. Plants require a lot of energy and water to grow, lots more energy to harvest, and are eventually transported over long distances before they get to their market. Sometimes the products even have to be preserved using chemicals to increase their shelf life.
With hydroponics, most of this energy can be cut out.
Hydroponic greenhouses can be set up in areas where crops wouldn’t thrive otherwise. As a result, the product can satisfy local demand without the long transportation process or questionable preservation methods.
Facilitates a Micro-Climate
You can grow hydroponic plants within a greenhouse or other similar structures. This means the plants can benefit from a microclimate, away from the hardships most farmers have to deal with.
The hydroponic system shields most crops from pests, climate, and soil degradation. With this method, farmers can grow their crops in a temperature-controlled environment with sufficient light and water and free of pests.
Farming using hydroponics is just easier than conventional farming methods. There’s no need for tilling, weeding, and applying herbicide or pesticide. This means quality yield with less manual labor.
Not only does this lower operational costs, but it also frees up time for other pursuits. As a matter of fact, a small hydroponic greenhouse can be managed by a single laborer.
Faster Growth Rate
Most fruits and vegetables take a few months to mature in traditional farming methods. This is because plants must extract nutrients from the soil, which can be slow. In addition, most of the nutrients they absorb are wasted in the maturing process. That isn’t the case with hydroponic plants.
The growth rate of hydroponic plants is from 30 to 50% faster than plants grown in soil. This system provides more nutrients for the plant to absorb.
The grower can also control temperature, light, nutrients, hydration, pests, and basically all the aspects of the process. As a result, they can streamline the process for faster growth or produce plants with higher yields.
Easier To Harvest Mature Plants
Hydroponics plants are basically grown on benches, planters, or tables. This puts them at waist height for most farmers.
The plants are easy to harvest at that height because there’s no need to squat or bend down. This makes it especially easier for gardeners with physical challenges or mobility issues to farm whatever they’d like.
Predictability and Seasonality
Typically, strawberries are cheap and fresh in the summer. However, in the winter, they’re scarce, and if you find them, they’re expensive and not as fresh.
In addition, unexpected natural occurrences like drought or floods could wipe out a whole field of crops. Seasonality is one of the circumstances conventional farmers must deal with.
In hydroponic greenhouses, the grower controls the conditions. This means that you can enter into long-term contracts because you can grow the product all year round. With seasonal products like strawberries, this means selling your fresh produce at higher rates when it’s not in season.
Reduced Reliance on Chemicals
Hydroponic systems don’t depend too much on fertilizers and chemicals to increase production.
Since there’s no wastage of resources in hydroponics, most of the nutrients the plants require are supplied without additional chemicals. This saves on operational costs and increases the quality of produce.
Disadvantages of Hydroponics
As we’ve seen, there are massive advantages to using hydroponics. However, like most other farming methods, there are considerable drawbacks too.
Therefore, it’s important to learn and understand all the disadvantages before committing to the system to avoid surprises.
Below are the main disadvantages of using hydroponics:
Requires Time and Commitment
Like any other venture, farming requires hard work and commitment to succeed. However, in traditional farming methods, plants can be left out in the field for days, weeks, or even months. This is because the soil regulates PH levels and anything not balanced out. As a result, plants can take a few days to die even when you fail to water them.
Things are pretty different in hydroponic gardens.
Without proper care and adequate knowledge, plants could die out in just a couple of hours. After initial installation, you must take care of the plants and system to ensure everything is running smoothly.
You can later automate the hydroponics system, but routine maintenance will still be necessary. You’ll also need to be ready to deal with unforeseen system issues at any time.
Big Initial Investment
Compared to traditional systems, hydroponics is expensive to acquire and set up.
Expenses range from equipment like pumps, pipes, net pots, and greenhouses to set them up in. The operational costs include high electric bills for the lights and equipment like pumps. This will set you back tens of thousands of dollars more than tilling farmland.
Furthermore, hydroponic greenhouses are much more difficult to ensure in some places. This is because the technology is still not well understood by insurers.
Acquiring financing to set up a hydroponic greenhouse is also more challenging than conventional farming methods.
Low Return on Investment
Although more farmers are opening up to the concept of hydroponic farming, its business models are still not well understood.
Commercial gardeners still face major challenges when setting up large-scale hydroponic farms. This is primarily due to the hefty initial investment, high operational costs, and uncertain return on investment.
There’s no clear way to detail a profitable plan to attract more farmers and investors into the sector. On the other hand, there are similar farming technologies with more promising financial prospects. Most large-scale investors are, therefore, hesitant to get into hydroponics.
Vulnerability To Power Outages
Hydroponics relies heavily on technology. This means that the whole system runs on electricity. So, if you don’t take preliminary actions to safeguard it from power outages, it’ll stop working immediately, and plants may die. As a result, backup power plans are necessary, especially for large-scale plants.
Steep Learning Curve
Since hydroponic systems run on several mechanical and electrical devices, they require hands-on knowledge to operate. The plants won’t do well unless a skilled expert controls the whole system. Even a minor mistake can interfere with the system’s operations and kill all your plants.
As a result, if you want to manage a hydroponic greenhouse yourself, you’ll have to take a few classes to familiarize yourself with the technology. The only other option is to hire a skilled professional to run it for you. In both cases, you’ll require significant time and money investments.
There have been long-running debates on whether hydroponic plants should be certified as organic.
One group questions whether hydroponic plants get the same microbiomes as when they’re planted in soil. Another group says there are organic methods to grow hydroponic plants. For example, some hydroponic farmers provide microbiomes for their plants using organic growing media such as coco coir.
As it stands, hydroponics aren’t certified as organic, and it’s not certain what the future holds. However, many researchers are working to end this debate, and, hopefully, there’ll eventually offer a definite answer.
Faster Spread of Pests and Diseases
While it’s true that hydroponic plants are less vulnerable to pests and diseases, it doesn’t mean they’re immune.
Since you’re growing plants in an enclosed environment using water, any pests or infections can escalate quickly to plants using the same reservoir. While this might not be a huge problem for home gardeners, it’s a major headache for large-scale hydroponics gardeners.
These big greenhouses can lose all their plants from a few gallons of contaminated water. As a result, they need to have rigid disease management plans. For example, if they realize the water is contaminated, they need to quickly sterilize the infected water, nutrients, and the whole system.
Risks of Water-Based Microorganisms
Since water plays such a pivotal role in hydroponic systems, the risk of water-based microorganisms is inevitable.
Although some bacteria and fungi are safe for plants, others can be deadly. As a result, hydroponic gardeners need to test their water before starting operation.
Water and Electric Safety
Hydroponics stand on two pillars: water and electricity. In the wrong circumstances, these two put together are a severe hazard. Therefore, hydroponic farms, especially commercial ones, need to take extra precautions to ensure a safe working environment.
Factors To Consider Before Starting Hydroponic Farming
As we’ve established, there are numerous advantages and disadvantages of hydroponics. Of course, whether it’s a worthwhile venture will depend on your circumstances.
If you feel that the benefits outweigh the shortcomings and would like to start hydroponic farming, you should consider a few things.
Availability of Water
Although hydroponics crops require less water to grow, you’ll still need considerable volumes to start farming. In addition, the water should be pure enough (98 to 99%) to keep the plant nutrients in the correct balance. Most hydroponics gardeners use Reverse Osmosis (RO) water to achieve this.
Since hydroponic plants don’t use soil, they require an alternate support substrate. Like soil, substrate materials hold the nutrients, air, and moisture the plant requires to grow. Substrates can be natural materials, such as:
- Pea gravel
- Coconut fiber
- Peat moss
They can also be artificial, like expanded clay pellets or rockwool.
Sunlight offers the full spectrum of visible and non-visible light. Therefore, it’s the best and the cheapest way to provide light for hydroponics. Since most vegetables require six hours of sunlight a day, southern-facing windows and most greenhouses can provide this.
However, if you don’t have access to this or want to grow vegetables in less sunny seasons, you’ll have to use grow lights. Bulbs with an output range between 4000 and 6000 Kelvin can provide cool (blue) and warm (red) light. When using artificial lighting, additional hydroponics equipment like structural support for lighting, light fixtures, accessible outlets, and power strips might also be required.
Plants require many nutrients to grow, and with the absence of soil, you’ll have to provide these nutrients yourself. Most hydroponic growers prefer buying a hydroponic premix containing all the required nutrients. The primary nutrients you need include:
Hydroponics is an innovative method of growing plants in spaces and seasons that would have otherwise not been productive. This system’s advantages include water conservation, space maximization, higher yields, and less labor. However, some disadvantages exist, like a low return on investment, a big initial investment, and the risk of water-based microorganisms.
All in all, hydroponics is an excellent option, especially for home gardeners with limited space. You can start small and later expand if the model is successful.