What’s The Difference: Hydroponics Vs. Aquaponics Vs. Aeroponics
May 9, 2018
Three distinct systems – all vying for the top spot in the niche of alternative growing systems.
What differentiates these three systems from one another? What makes them work? These are the areas that we will be tackling today.
Hydroponics vs. aquaponics vs. aeroponics – which one is the superior system?
What Is It?
The principle of hydroponics is the oldest among the three because the use of soil-less setups has been around since the age of the Hanging Gardens of Babylon.
A hydroponics system has two main parts: the grow beds and the reservoir.
The reservoir contains the nutrient solution or the water mixed with various nutrients that plants need in order to grow successfully in the media bed. The grow beds, on the other hand, contain the media and the ‘cups’ that will hold the plants in place.
To clarify, growth media will replace soil in a hydroponics setup. There are many kinds of growth media to choose from: coconut coir, perlite, organic-polymer composites, rockwool, etc.
Among the beginning enthusiasts market, the most popular is coconut coir because it’s 100% organic, expands tremendously with water and can accommodate plants easily – with spectacular results.
Perlite, on the other hand, is hailed as a near-perfect medium for growing plants but it is particularly light, which makes it problematic for flood and drain systems as it can easily float away along with the small current of the water in the grow bed.
Organic-polymer combos/composites like Perfect Starts are becoming increasingly popular because they’re easy to use and are not deformed when germinating plants are transferred from the growth trays to the main growing beds.
And finally, we have rockwool. Rockwool is a type of reusable media as it can be sanitized with steam washing after every growing season.
Rockwool is actually melted rock spun into slabs and other shapes/sizes for the purpose of growing plants.
The main point of contention with rockwool is that it’s not very environmentally friendly and thus, it goes against the main principle of switching to a more environmentally friendly method of cultivating plants.
The type of media used in a hydroponic system is so important because it will dictate the efficiency in which plants will be able to absorb the nutrients from the solution.
One of the key problems with hydroponics is that roots sometimes succumb to low oxygen levels, which predisposes crops to premature death.
A solution that growers have found effective in dealing with poor aeration and oxygen zone issues is combining two kinds of media to get the best attributes of each one.
Our personal recommendation would be to combine 50% coconut coir with 50% perlite.
Perlite is amazing when it comes to absorbing and delivering moisture plus it also improves the overall aeration of the plant’s root area. Both are highly regarded in the hydroponics community and both are also widely available to growers everywhere.
Tip: Coconut coir can be made more effective with the addition of perlite.
Hydroponics Pros And Cons
The main advantage of hydroponics is it’s designed for long-term cultivation of almost any kind of crop.
Commercial hydroponic growers harvest hundreds of kilograms of crops easily using large rockwool slabs.
The system simply works and can be easily expanded if you want to make money off your hydroponics system.
The downside is that with the booming interest in hydroponics in recent years, the price of the chemical compounds needed to create a viable nutrient solution has been steadily rising due to the over-mining of these minerals.
Another problem with hydroponics is that it uses relatively more water because after a time the buildup of salts becomes too much for the system and water has to be replaced so as not to kill the plants.
Also, there is a need to check the electrical conductivity of the water every day to make sure that the pH of the water is just right. Fluctuations in the pH level of the water can damage plants and eventually cause a die-off.
Aquaponics is a hybrid system that combines the best of aquaculture and hydroponics. System-wise, it looks like a hydroponic system, but instead of relying on a main reservoir that contains a nutrient solution, the source of nutrients will be a vat of live, swimming fish.
How does this work? When you feed fish, the fish will naturally excrete waste. The waste mixes with the water, increasing the ammonia levels.
Obviously, this waste has to be mediated and reduced, so as not to kill the fish. Normally, fish tanks are regulated by biological filters and other types of filters that neutralize ammonia and reduce the impact of feces on the fish.
In an aquaponics setup, water from the fish tank is recirculated throughout the system so that it passes through the grow beds, where crops are steadily being cultivated.
The plants absorb dissolved nutrients in the water and process ammonia, which is highly toxic to fish in increased levels.
Bacteria residing the in the roots of plants, as well as good bacteria from the gut of fish work together to establish a balanced ecosystem where both fish and plants will survive.
After about half a year, the mini-ecosystem formed by an aquaponics setup will begin to show signs of high-level, self-regulation.
This will be the time when both fish and plants will begin to truly flourish. There will be great increases in both fish yield and plant yield, and the maintenance of the system will become even easier.
Tip: Be sure to check the roots of plants for signs of rot.
Aquaponics Pros And Cons
The best thing about aquaponics is you will be essentially hitting two birds with one stone – you will be raising fish and growing crops at the same time.
Fish waste, which is something that is regulated in aquaculture, will no longer be considered a problem because it becomes a sought-after source of nutrition for the plants.
Without fish waste, plants wouldn’t have nutrients.
The plants, on the other hand, will serve as a 24/7 ammonia control center for the fish tank, reducing the ammonia load and preventing toxicity in the water.
Fish are sensitive to ammonia and even a small increase in the ammonia content in the water can cause stress, shock, and disease.
Additionally, aquaponics growers now add red worms to the grow beds to increase the efficiency of waste breakdown and subsequently, the distribution of nutrients to plants.
Red worms are first grown on soil and upon adulthood, they are then soaked/washed and then transferred to the growth bed of an aquaponics setup.
The process of breaking down physical waste into smaller particles through the digestive action of red worms is – you got it right, composting!
Yes, it is amazing to imagine that you can actually compost organic material on a grow bed, on stuff that isn’t actually soil.
But there you have it – red worms do the job quite splendidly.
In addition to helping improve the nutrient levels of the water being fed to the plants, there is another big reason why red worms are now being regularly included in aquaponics systems: e. coli.
E. coli is a common pathogen/bacteria found in fish feces. E. coli infections can bring down a full-grown, healthy adult and bring him to the hospital.
Imagine what a widespread e. coli outbreak can do to a tank full of fish, with no other place to hide from the swimming bacteria.
E. coli colonizes fish feces, so these need to be broken down more quickly to prevent an e. coli outbreak from taking over the system.
Red worms can do this perfectly because they need to eat fish feces to survive.
Is there a downside to an almost perfect system? One of the downsides of aquaponics culture is you have to be very specific with the design of the system so you won’t have to shut it down during the winter.
Obviously, you can’t move large equipment and vats indoors, unless you have a really big house (or garage) but all the same, it’s an issue since frozen water can easily kill fish and winter does the same to plants.
Another downside to the system is even if you only want to grow crops for consumption or sale, you still have to tend to your fish well enough so they don’t continually die off.
Fish care can be learned and if you are a natural hobbyist and if you don’t mind looking at another component in a system, then tending to your fish won’t be much of a problem.
What is It?
Aeroponics is a variation of hydroponics, but instead of using a grow bed filled with media, the plants are instead suspended, with roots facing a sprinkler system connected to the main nutrient reservoir.
Depending on the plant and the design, aeroponics systems generally use little to no media at all.
Now, you may already be wondering – what is the point of all this?
Why not just use media like everyone else? Why do you have to install a sprinkler system that periodically sprays the roots of plants with the nutrient solution?
It all boils down to oxygen. Believe it or not, even if the roots of the plants are down there in the soil, these still need oxygenation in order to thrive.
One of the limitations of hydroponics is because the roots are also submerged in water and the media, there is often poor oxygenation, which hampers plant growth.
Aeroponics solves this problem by completely liberating the roots of the plants and allowing it to come into contact with pure air.
The results are astounding.
Crops grow two to three times their normal size and yields are simply amazing.
Root formations are also incredible. Normally, the taproot of plants only have a moderate amount of root hairs around them.
In plants grown using the aeroponics method, the roots flourish widely and the root hairs become really thick – a tangle of healthy root hairs just enjoying the exposure to oxygen.
Aeroponics Pros And Cons
As with any system, aeroponics has its own set of ups and downs. The main advantage of this system is crops grow incredibly quickly and the yields are high.
If you are after high yield and shorter growing periods, aeroponics is certainly something to think about, especially if you are already investing in equipment and space for this endeavor.
Aeroponics also uses the least amount of water over time and all excess water that isn’t used by the roots of the plants are simply drained back to the nutrient tank.
Tip: Always have backup power and an extra pump in an aeroponics setup.
The nutrient tank is checked daily, much like a conventional hydroponics system.
The pump and spray system is submerged in the water and through a simple timing mechanism, is able to deliver short mists of water to the roots of the plants.
And now for the downsides. Room air doesn’t store water, even if it’s really humid. Humidity is not enough to sustain the roots of plants at all.
Aeroponics is extremely dependent on the misting system. If something should happen to the misting system, then the plants can die easily as a result of dried up roots.
To avoid this, you have to plan ahead. The misting system needs to have backup power and you need to have a backup misting system too, in case the first one fails for some reason. This usually means having an identical pump waiting in store to replace the main once it breaks down.
The misting heads also need to be checked periodically for clogs. We recommend replacing these misting heads instead of just cleaning them to get optimum results.
Remember – your plants are at the mercy of the misting system. They’re not submerged in water and plants are like fish out of water when there’s periodic misting taking place.