Are you an at-home gardener looking for an alternative to backyard planting? Or perhaps you’re a larger-scale farmer ready to try a new method of planting? Regardless of your background, you’ve probably got hydroponics and aquaponics growing on your mind.
Hydroponics and aquaponics are both soilless methods for growing plants. Hydroponics relies on fertilizer-enriched water to provide plants with the nutrition and pH balance they need. Aquaponics combines hydroponics with aquaculture (fish keeping) to create a balanced ecosystem in which the fish waste is converted into nutrients for the plants and the plants naturally filter the fish water.
DIY hydroponic and aquaponic systems can be set up on a tabletop, and larger-scale systems are efficient means of growing for profit. Either way, the process begins with understanding the difference between aquaponics vs. hydroponics and determining which is right for your garden.
Ready to learn more? Let’s get started!
Aquaponics vs Hydroponics Quick View
Up to 18 months for full production
Up to 1 month for full production
Check water every 7 days, water changes usually not needed
Check water every 1-3 days, change water every 2-4 weeks
Best for leafy green, lettuce and herbs
Reliance on Electricity
Requires more space
Needs less space
How Aquaponic and Hydroponic Systems Work
Before we dive into the differences between the two growing systems, let’s take a quick look at how each one operates:
What is Hydroponics?
In hydroponics, the grower adds fertilizer to a water reservoir, and the system circulates this nutrient-rich water to each plant constantly or intermittently. The plants get their nutrients delivered directly, and the roots also have better oxygen exposure compared to those grown in soil.
Zach VanderGraaf, hydroponic grower and blogger at Love From Our Backyard, likes hydroponics for several reasons. “It’s great because it’s simple but effective at helping plants grow faster, larger, and cheaper than traditional soil-based systems. The downside is how you need to check the water all the time to make sure there’s enough, and you need to change the water to provide enough nutrients.”
Here’s an example of what one type of hydroponic growing system looks like:
Since hydroponic growing relies on added fertilizers, it is not guaranteed to be as natural and organic as aquaponic systems.
Hydroponic upkeep also requires maintaining the water’s pH level. Typically, that value should stay on the acidic side, somewhere between 5.5 and 6.5. This allows nutrients to be maximally available to plants.
Keep in mind that we’re barely scratching the surface here when it comes to hydroponics. To learn more, stop by the Pure Greens website and check out this Ultimate Guide to Hydroponics!
What is Aquaponics?
Aquaponics, on the other hand, is the blending of aquaculture (farming fish), with hydroponics.
“The fish add nutrients to the water through their waste, scaling, and natural bacterium. It’s great because it’s more natural and requires less ‘added nutrients’,” Zach says. “You also get to keep (or eat) the fish. Its biggest downside is the added cost and responsibility of keeping the fish on top of the plants.”
Instead of using fertilizers to support plant growth, aquaponic systems rely on the symbiotic relationship between fish, bacteria, and plants to farm both plants and fish.
Here’s the basic breakdown:
- Bacteria consume fish excrement, which helps keep the water clean for the fish.
- The bacteria also convert the waste’s ammonia into nitrate, which is a usable form of plant food.
- As the plants take up this nitrified nutrition, they are actively cleaning the fish’s water.
Here’s a visual to give you a better idea of how aquaponics works:
This cycle keeps the fish fresh and healthy while also providing nutrients for plant growth, leading to one of the coolest benefits of aquaponic growing: dual harvest.
If you choose edible fish such as tilapia, catfish, trout, or shrimp to grow in your aquaponic system, you can harvest them. But keep in mind that these fish require large aquatic spaces to grow, so these are only good options if your aquaponic tank is on the bigger side.
If you are just looking for a tabletop aquaponic setup, smaller fish like goldfish might be a better option. These won’t contribute to a dual harvest, but they will feed your plants just as well as the bigger fish do.
Aquaponics vs Hydroponics: What Are The Differences?
So know that you know the basic operating principles of hydroponic and aquaponic farming, let’s look at what sets these systems apart:
Aquaponics has a higher start-up cost, often by a significant amount. According to Emily Barbosa Fernandes, a small-space gardener and consultant at HouseGrail, expect to invest about $1400 for a backyard-friendly aquaponics system. If you’re considering a large-scale operation, the set-up costs may reach about $20,000.
These are the main contributors to the cost:
- A large tank
- A powerful filtration system
- Grow media
- Purchasing fish
- High-quality fish food
Over time, though, aquaponics may end up being the less expensive route. Many of the costs are one-time charges, and once the system is up and running optimally, it takes care of itself to a large degree.
Setting up a productive hydroponic system typically costs quite a bit less. Emily says, “If you’re looking to grow a small herb garden and want a low-tech system, it can cost between $50 to $200, and for a medium one, between $300 to $1,000. For a high-tech system, it can cost more than $10,000.”
However, hydroponics does have the added cost of purchasing fertilizers, and that’s an ongoing cost. Depending on the current market supply/demand, fertilizers can be a pretty considerable expense.
Because you’re essentially establishing an actual ecosystem in your aquaponics set-up, it takes time to achieve a balance that’s healthy for fish and plants. It can take anywhere from 3-6 months to build a thriving microbe population to convert fish waste into usable nutrients for your plants, and up to 18 months for optimal produce production.
With hydroponics, the initial stabilization process is much shorter. It typically only takes a couple of days at most to get your nutrient and pH levels adjusted to support plants, and about 1 month for optimal plant production.
Vulnerability to Plant Disease
Root rot, or fungus that attacks/destroys plant root tissue, is a common problem in hydroponics. Keeping your hydroponic tank properly cleaned and monitoring your plant health closely can greatly reduce the chance of root rot, and routinely treating your tank with hydrogen peroxide is another effective step.
Interestingly, root rot almost never happens in aquaponics. In all likelihood, the friendly microbes that fuel the aquaponics system don’t allow the harmful fungi to get a foothold.
Upkeep and Maintenance Needs
No matter which growing system you choose, you’re looking at some routine monitoring, maintenance, cleaning and upkeep. But the specific tasks you’ll need to perform are a bit different:
- Routine monitoring
- Water changes and cleaning
Routine monitoring. Hydroponics is a more precisely-calibrated method than aquaponics, and you’ll need to check your system’s electrical conductivity (EC), pH, temperature, nutrient levels and other factors every 1-3 days.
With aquaponics, you only need to check ammonia and pH about every 7 days or so.
Water changes and cleaning. A sterile growing system is your goal in hydroponics, and it’s definitely the more labor-intensive of the two systems. You’ll need to perform complete water changes typically every 2-4 weeks, and you’ll also need to clean your reservoir with diluted bleach or hydrogen peroxide on a regular basis.
NOTE: That discarded water from hydroponics is extremely high in nutrients, which could disrupt balances in natural ecosystems. That’s worth keeping in mind, especially if you live in an area that already has problems with phosphorous/nitrogen overload.
On the other hand, you almost never have to do a full water change in aquaponics- just periodic top-ups for water loss due to evaporation or plant transpiration. Even when you do need to discard aquaponic water, it will have minimal to no effect on natural ecosystems since there are no artificially high nutrient levels.
Troubleshooting. Aquaponics can be more difficult to manage if something goes wrong. Since you’re raising fish in addition to your plants, there are more variables to take into consideration and more system parts to inspect when investigating an issue.
You’ll also need to monitor fish population. If your tank becomes overcrowded, the fish produce excessive waste that could clog/damage the system. But that’s actually a good problem to have- time to harvest some fish for dinner!
Problems in a hydroponic system are typically easier to diagnose and treat. Most of the time, adjusting the pH, adding some hydrogen peroxide to the tank or trying a different nutrient balance will correct the problem.
Organic Certification and Sustainability
Hydroponics is not an “organic” growing method since it relies on chemical nutrients. But even though it’s not technically “organic,” there are other health and safety certifications that hydroponic growers can earn. And hydroponics will almost always be lower in pesticides and herbicides than crops grown conventionally in the soil.
Conversely, aquaponics is a more holistic approach: It takes advantage of a natural symbiotic relationship to reduce the need for chemical fertilizers and pH modulators. Thanks to this, aquaponics is a naturally organic method, and it also meets the criteria for truly sustainable growing.
Hydroponics produces a most more consistent yield, and it’s much easier to estimate costs once the system is calibrated and functional. In other words, once you fine-tune your growing process, you can reliably replicate it as many times as you want in the future.
Since there are more active components to aquaponics and the system is based on a natural function/cycle, harvests and growing timeframes can vary more. For example, if even one fish becomes ill, it can throw off the entire ecosystem for a time.
However, many aquaponic growers find that after they’ve established a healthy ecosystem, their yields are comparable or even occasionally better than some hydroponics systems. And you can’t overstate the benefit of being able to harvest both fish and produce from your aquaponic tank!
Since aquaponics relies on naturally-produced plant food, you don’t have the high and perfectly-calibrated nutrient levels that hydroponics offers. Because of this, aquaponics typically can’t support heavy-feeding plants (like tomatoes or peppers), and it’s best for non-fruiting plants like leafy greens, lettuce and herbs.
On the other hand, hydroponics offers a wider range of plant options since you can tailor the nutrient concentration minutely to support the needs of almost any plant.
While there’s nothing holding you back from growing whatever your heart desires in a hydroponic or aquaponic garden, a little forethought can save you a headache.
You might be wise to avoid plants that take up a lot of space, including these:
Similarly, burrowing root vegetables are likely better off in the dirt. A few examples include the following:
Reliance on Electricity
Power outages and downtime can adversely impact an aquaponic system much faster than a hydroponic one. The filters in an aquaponic system run on a much shorter interval, so loss of electricity can lead to dangerous waste build-up faster.
In general, aquaponic systems tend to be larger than hydroponic ones, owing primarily to the fact that you need additional space for your fish tank. Even with two plant growing beds that are the same size, an aquaponic system is typically at least twice the size of a hydroponic one.
Investing a spacious fish tank is critical for aquaponics success. Crowding too many fish into a small tank not only leads to serious problems with crop production, system function and fish health, it creates inhumane living conditions for the fish.
A hydroponic set-up is much more compact. While you can certainly scale your hydroponic garden as large as you want, you can have a fully operational system using just one 5-gallon bucket or large plastic tote.
How Are Aquaponics and Hydroponics Similar?
Both hydroponic and aquaponic growing systems have several common benefits to offer:
No Need for a Large Outdoor Space
Hydroponic and aquaponic gardens can live inside, so they are great for growers who have small yards or no yard at all.
With fresh, affordable food being a scarcity in some areas, hydroponic/aquaponic growing could help provide needy communities with healthy food.
Fewer Pests and Plant Diseases
Since hydroponic and aquaponic gardens are usually fully indoors or in a sheltered outdoor location, the plants are far less likely to be attacked by insects or disease. Most of these plant enemies are introduced on the wind or from neighboring infected plants, and some insect larvae/disease spores can live in the soil for a few years.
Because hydroponic/aquaponic plants are protected from invaders and sickness, you’ll to apply pesticides or herbicides far less or not at all.
Less Prone to Seasonal Limitations
Since hydroponic and aquaponic gardens can be set up easily in greenhouses and indoor spaces, they are less affected by the winters’ frosts and shorter daylight hours.
This allows growers the flexibility to grow year-round, and to expand their options for which crops can flourish in colder seasons. Also, it makes fresh food production available to people who live in climates where the outdoor growing season is prohibitively short.
In both types of systems, water is recycled within its tank, so the growing process is much less water-intensive than conventional farming.
According to United States National Park Service, it’s estimated that hydroponics uses just 1/10th of the water than soil-based growing requires.
It’s Fun and Educational!
For those used to traditional gardening, playing with a new method of growing is an exciting challenge.
Plus, hydroponic and aquaponic systems are kid-friendly and educational for classrooms.
Learning about aquatic cycles as well as plant growth is accessible and exciting when you can see your plants’ roots grow and see how fish or fertilizers are nourishing them.
Starting Your Growing System
Getting started with hydroponic or aquaponic gardening may sound like a tall order. But it’s really not!
Here’s a look at the supplies and knowledge you need to start your own growing system.
You can buy aquaponic tanks of all varieties and sizes online, like this small at-home tank from Amazon:
Back to the Roots Indoor Garden
If you are feeling crafty, there are plenty of options for DIY-ing your aquaponic system. This is a straightforward aquaponic recipe of sorts, pulling together the pieces you will need to make a mini aquaponic garden and how to construct it.
To see more options for varying aquaponic setups, check out this helpful video from Rob Bob’s Aquaponics and Backyard Farm:
If you’re looking to grow just a few plants at a time, a hydroponic set-up can be as small as a counter-top system:
Frequently Asked Questions about Aquaponics vs Hydroponics
All that is to say, there is no one right way to do hydroponic or aquaponic gardening.
Both growing systems have their benefits and drawbacks. When it comes to choosing the best one for you, spend some time thinking about your space, time, budget, and intended harvest.
Then go forth and get growing!
What are your thoughts on aquaponics and hydroponics? Have you tried either method, and what was your experience like? Do you have any other questions?
Let us know in the comments!