What are aeroponics vs hydroponics, how are they different and which is better?
Aeroponic growing is a system where plants are suspended in the air and a mist containing a nutrient solution is sprayed over the roots. On the other hand hydroponic growing is where plants are grown in a nutrient solution, without soil. Technically, aeroponics is a type of hydroponic growing, but they are often considered two competing processes. Whilst they are similar they do have some key differences that I will dive into.
To give you some context, both the terms aeroponic and hydroponic come from Latin words and they mean labor of water and labor of air, respectively. Hydroponics are a little more beginner friendly and cheaper to get started with whereas aeroponics can be more expensive and complicated to set up but they take up less space, they also have a more sleek appearance.. Aeroponics is a more innovative process which was established to fix the problems found in hydroponic growth techniques.
It can be overwhelming trying to decide which method might suit you best because there’s so much information available. Some of it can be very technical and scientific. I’ve spent hours and hours researching these two growing methods. I have used this research as well as my scientific background to break down these processes into more easily understandable information.
In this article, I will outline and explain aeroponics and hydroponics. This will include how they work, who these methods might suit and also their similarities and differences.
Table of Contents
- What Are Hydroponics?
- How Do Hydroponics Work?
- What Are the Benefits and Drawbacks?
- Why Do Roots Need Oxygen?
- Why Can’t the Roots Get Water?
- How Can I Oxygenate My Plant Roots in Hydroponic Systems?
- Why Were Aeroponics Developed?
- Low-Pressure Aeroponics (LPA)
- High-Pressure Aeroponics (HPA)
- Ultrasonic Fogger Aeroponics (Fogponics)
- What Are the Benefits and Drawbacks?
- Which Is Better: Aeroponics or Hydroponics?
- The History of Aeroponic and Hydroponic Systems
What Are Hydroponics?
Hydroponic growth systems are a mechanism whereby crops and plants are grown without using soil. Usually, plants absorb all of the minerals and nutrients they need through their roots via diffusion and osmosis from the soil. When hydroponic methods are used the plants get their nutrients through an aqueous solution supplied to the roots.
Hydroponics can be a large scale project for mass production of crops or a tiny collection of plants at home. Hydroponic growing is especially useful in areas with very limited land or for people who want to grow vegetables at home but don’t have a garden.
Generally, you CAN grow anything with a hydroponic system. But most people advise that you stay away from plants that grow super tall or vining, such as corn or potatoes since they take up a lot of room due to large root systems. All leafy greens are excellent candidates for growing in a hydroponic system, as well as herbs, peppers, tomatoes and lettuce.
How Do Hydroponics Work?
Very simply put, plants make energy via a process called photosynthesis. This requires light (artificial or sunlight), the key minerals and nutrients and water. A hydroponic system replicates the required environment in a traditional garden by providing a nutrient rich solution straight onto the roots. Many hydroponic grow systems have a set of grow lights to mimic sunlight.
Not all hydroponic systems are the same; the plants are either suspended so the roots sit within the aqueous solution or they are grown in a soil-free medium. This could look like LECA, perlite, coco coir, rock wool or vermiculite.
What Are the Benefits and Drawbacks?
Possibly the biggest benefit when it comes to hydroponics is the fact it is more user friendly than an aeroponic system. The set-up is straightforward. It is more affordable and once it is up and running it is fairly low maintenance. On the environment side of things, it is possible to do without electricity which is a plus! You can grow a higher density of plants, and additionally it recycles the water that is used – all in all pretty good going. However, nothing is perfect as we know. Potential drawbacks include it’s aesthetic (it could look like a big eye-sore in your living room). Your plants may also be more susceptible to diseases in the water, as well as this system using more water and fertiliser in general. It also requires a growing medium, such as perlite or sand.
Why Do Roots Need Oxygen?
It’s important to understand how a plant grows in order to comprehend the mechanisms of aeroponics and hydroponics. In particular, it’s key to know why roots need oxygen and how to supply it in order to keep hydroponics a viable option for growing plants. The roots of a plant play a few vital roles. Firstly they anchor the plants in place and, most importantly, roots absorb minerals the plant needs in order to grow and stay healthy. Roots burn glucose which is transported from the leaves and turn it into a different type of energy, called ATP (adenosine triphosphate). This transformation of glucose to ATP happens during cellular respiration. This occurs at night when the plant is not photosynthesising (hence why plants need darkness).
For respiration to take place oxygen is needed as it plays a crucial part in anaerobic respiration. Without a lot of oxygen readily available for the plant’s roots the plant is limited in growth which results in poor yield and low quality crops. This is because many of the nutrients that crops need in order to survive can only be absorbed if there is sufficient oxygen. These weakened plants are also more likely to be affected by plant diseases and are also less able to cope with environmental stresses such as drastic temperature changes.
Plant growers have had a few technologies to aerate water for plants but they are largely ineffective. Oxygen diffusers are often used but they are low in efficiency for example. Many growers also use chilling systems as cold water is better at holding diffused oxygen than warm water. Chilling systems rely on a large amount of energy to run, which makes them very expensive and less environmentally friendly.
Why Can’t the Roots Get Water?
One part of the problem when it comes to oxygenating the roots of the plant in hydroponic systems is that growers will be using warm water. This in fact holds oxygen less efficiently than cold water. A further issue is with circulation. For example if the water within the hydroponic system is not circulating with access to air there is no way for more oxygen to diffuse and dissolve in the water. Since hydroponic systems recycle their water this can become a huge problem unless the water is manually oxygenated.
How Can I Oxygenate My Plant Roots in Hydroponic Systems?
There’s many ways to increase the oxygen levels in a hydroponic system. Such as air pumps, oxygen gaps or air diffuser tubes.
Air Pumps or Air Stones
This is probably the most commonly used way to provide extra oxygen into your water because these things are an easy and affordable option. An air pump will push air directly into the air stone which breaks the bubbles and creates small oxygen rich bubbles. They are available in loads of shapes and sizes to ensure all areas are covered. The primary drawback is that you could need a lot of them in order to consistently cover all sections of the hydroponic system.
Air Diffuser Tube
An air diffuser tube is a circular tube that has holes which allow oxygen to permeate into the water. Small and large bubbles are created which will rise at different speeds allowing for a longer boost of oxygen.
An oxygen gap means an area within the hydroponic system that is just air and no water. They are created by installing a reservoir with outflow, providing drainage for water before it re-enters the system. The water that is exposed to the air during this step allows oxygen to go to the roots.
Why Were Aeroponics Developed?
The roots of plants need oxygen. Hence why root rot is a big problem when you overwater. As discussed hydroponics faced a huge problem where the roots weren’t able to get any oxygen. Researchers aimed to solve this problem by using pumps to deliver oxygen to the roots in the water. Unfortunately, this mechanism proved to be ineffective, because the oxygen was delivered unevenly and it tended to not be enough to sustain them.
Scientists decided to try spraying the nutrient solution onto the roots of the plant. In 1983 aeroponic kits were available to buy commercially.
There are different types of aeroponic set ups, low-pressure aeroponics, high-pressure aeroponics and ultrasonic fogger aeroponics called Fogponics for short.
Low-Pressure Aeroponics (LPA)
LPAs are the best options for beginners and hobbyists as they use the least tools and experience. They require a pump, a reservoir, sprinklers and a root chamber platform.
They are the easiest to maintain due to the small amount of parts required. LPAs can work with a lot of different plants. However, LPAs are not ideal for large gardens and they don’t provide as many nutrients as efficiently as a high-pressure aeroponic system.
High-Pressure Aeroponics (HPA)
In these systems the water is atomized to a fraction of the size as in low-pressure systems. The water droplets are less than half of the width of a human hair! This is more effective for the roots and allows them more access to oxygen which is perfect to increase plant growth. Plants grown in HPA systems are often stronger, healthier and larger because a greater volume of oxygen allows the roots to absorb nutrients better.
The drawback of HPA systems is that they require specialized equipment such as unique sprinklers, as well as a more powerful pump. HPA systems also demand more time for set up and maintenance. Obviously, HPA systems therefore require a large amount of knowledge and experience, making them more suitable for larger-scale growers or farmers.
Ultrasonic Fogger Aeroponics (Fogponics)
This type of aeroponics involves a method where water is atomized to such tiny molecules that a fog is produced rather than a mist such as in LPAs and HPAs. The water molecules in the system are around the size of a red blood vessel. These tiny water droplets are perfect for young plants and sensitive plants such as herbs, cloning and plantlets. Fogponic systems are much more difficult to set up and maintain, particularly if you haven’t got much experience growing in aeroponic systems.
What Are the Benefits and Drawbacks?
Let’s start with the benefits. The biggest difference with aeroponics comes down to plant health. The plants will generally grow faster and healthier as this method has a higher nutrient absorption rate. There is also no need for a growing medium (one less thing to think about!). Followed by the sleeker look, easier to handle and the ability to be a productive system in a small space, aeroponics definitely has major benefits.
Although these benefits come with drawbacks as you might expect. To set up, it will require a higher initial cost as this system is more technical than hydroponics. You are also limited to a closed environment unlike hydroponic systems. Say you’ve splashed out on this quite advanced technology, what could go wrong you ask? Potential technical difficulties. Be aware of possible power outages, glitches, and anything else that may crop up. That is to say technical knowledge would go a long way, this is quite a complicated piece of equipment!
Which Is Better: Aeroponics or Hydroponics?
Quick Look at Hydroponic vs Aeroponics
|Plants grow up to 300% faster than in soil||Plants grow up to 30 – 50% faster than in soil|
|Generally more productive||Tends to yield less plants|
|Work in a closed environment which prevents water evaporation||Can work in a closed or open environment|
|Aeroponic systems save 95% irrigation water||Hydroponics saves 80-90% irrigation water|
|Aeroponics saves around 85% fertilizer||Hydroponics saves 55-85% fertilizer|
Aeroponic and Hydroponic Systems Yield Similar Sized Crops
An experiment was done with sunflowers to test whether hydroponic or aeroponic systems lead to faster growth. Hydroponic systems initially seemed to be more successful as the plants were growing faster, however this is probably due to the fact hydroponically grown plants can establish their roots more quickly. After a few weeks the aeroponically grown plants can compete with the others, boasting a much larger size. Six weeks into the experiment the aeroponic plants were roughly 30% bigger than the hydroponically cultivated sunflowers.
However, further research has had various results showing hydroponic systems eventually level out and the growth rate becomes quite evenly spread.
Simpler Transplanting With Aeroponics
One key advantage of aeroponics in comparison to hydroponic systems is that it is so much easier to move any plants. There is no need to remove your plants from a growing medium as they are suspended in the air with their roots exposed. Not only will transplanting them be easier but it is also safer for the plant and less likely to cause damage to their roots. This also means you inspect the whole of your plants without disturbing them.
The History of Aeroponic and Hydroponic Systems
Plants growing in water are as old as time. Plants grew in oceans and in lakes much before they ever grew on land. Farmers have been using hydroponic gardens for thousands of years. Historians believe that the hanging gardens of Babylon were potentially the first example for instance. It is thought that the gardens were planted along the Euphrates River and the water was carried to a peak and then allowed to trickle down through the gardens. There’s Greek scientific studies from 300 BC showing hydroponic experiments, and there’s even Egyptian hieroglyphics showing plants being grown in the river Nile.
Experiments by botanical scientists have been taking place since the 1600s but the term hydroponics wasn’t actually created until 1924. Dr William F Gericke created the term to describe crops growing in non-soil media. His work is considered the foundation of all forms of hydroponic growing even though the actual mechanisms are now very different, we have Gericke to thank!
Throughout the second world war hydroponics were used in order to grow food for soldiers stationed in remote locations where the soil was not suitable for traditional farming methods. From 1952 the U.S army actually has had its own hydroponics branch which produces millions of pounds of fresh fruit and vegetables. From this point on many other countries began to use hydroponics commercially and by the 1960s alternative growing methods became a world-wide industry.
Aeroponics were later developed as a response to the problem of oxygen in a hydroponic system, by suspending the plants in air and having the roots suspended they have access to oxygen constantly.
FAQs About Hydroponics and Aeroponics
Is aeroponic better than hydroponic?
It’s hard to say which is better, because it does depend on who is looking and what they want to grow, but they’re both sustainable and efficient. Aeroponics offer the benefits that they are faster, tend to result in a much higher yield and the mechanism leads to better nutrient absorption. However, aeroponic systems are challenging to build and more complicated to set up for beginners.
What are the disadvantages of aeroponics?
Aeroponics are more expensive than hydroponics to set up due to the number of nozzles needed to spray the entire root system every few minutes. Setting up an aeroponic growth system could cost you around $200 – $1000 depending on whether you buy a ready made set or build it up yourself. This means it’s a lot less accessible for most home growers.
What are the disadvantages of hydroponics?
The main issue with hydroponic growth systems is the susceptibility of the plants and crops to disease. These are usually water-born diseases, but these can be dealt with by using thorough cleanings and anti-bacterial products. Another disadvantage is that hydroponic growth systems use a lot of water, fertilizers and space. This makes them a little less budget friendly in the long run and also less sustainable.
Is aeroponics more expensive than hydroponics?
Aeroponics are more expensive than hydroponics, especially in terms of the initial cost to set up and get running. This is mainly due to the fact that aeroponic systems require a lot of specialist equipment to be able to deliver those nutrients to the roots. Since the roots require moisture to be delivered every few minutes throughout the day and night it takes a lot of energy to run, plus the nozzles can’t be too far from the roots so the system will require a lot of nozzles.
How much faster is aeroponics?
One NASA study showed that plants can grow up to three times faster in aeroponic growing systems than in soil. Not only that but the study suggested that the yield of these plants is more consistent than their soil-grown counterparts.
The Bottom Line When It Comes to Alternative Growing Methods
Both systems work by delivering nutrients to the plant via an aqueous solution containing minerals and nutrients. The main difference in the two systems is how they deliver the aqueous solution. Ultimately, hydroponic and aeroponics systems are very cool and will be quicker and more consistent than growing in soil, whilst providing a gorgeous yield. Aeroponics is a much newer, more innovative technology. This means hydroponic systems are more common because they’ve been around a lot longer.
Hydroponic and aeroponic systems are more important than ever before due to water shortages and climate change. Our soils are decreasing in quality due to widespread monoculture practices. We need to reduce water consumption in order to maintain a sustainable amount of water for human life. Aeroponic methods can reduce and streamline the resources required to grow our foods since they use 95% less water than traditional methods.
We can’t wait to see where hydroponic and aeroponic methods go next!
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