Setting up an aquaponics system can be a rewarding experience if you’re passionate about fostering aquatic life and supporting plant life through a hydroponic approach. But for your system to work, you need to ensure that it has all the essential components.
Here are 11 things that every aquaponics system needs:
- A sturdy tank
- Fish-safe water
- Fish food
- A media bed container
- A growing media
- A basic waste filtration system
- An effective draining system
- Consistent maintenance
- A well-thought-out plan
Read on to learn more about the above aquaponics essentials and what you can do to build a flourishing ecosystem.
1. A Sturdy Tank
Much like a hydroponics system, an aquaponics system requires a substantial volume of water. Aquaponics systems need to sustain fish and plants, and the tank needs to be large and sturdy enough to support that.
Some people choose to use large acrylic tanks explicitly made for fish aquariums. However, it’s also possible to repurpose other food-grade containers provided they’re sturdy and large enough to hold a substantial amount of water and fish.
The tank-plant bed ratio is a crucial consideration when choosing tank sizes. This ratio needs to be large enough to support healthy biological filtration because you’ll need enough plant bedding to sufficiently filter out the ammonia produced by the fish. If the ammonia in your tank isn’t sufficiently filtered out/broken down, it can be toxic to the fish.
Your ideal tank-grow bed ratio will vary based on various factors:
- The type of fish you have
- The number of fish you’ll have
- How much you plan to feed your fish
The rule of thumb is to start with a ratio of 50 sq. ft (4.65 sq. m) of plant bed (or biological surface area) for every 1 pound (0.45 kg) of fish. To facilitate that, go for a tank capacity of at least 250 gallons (946 L). The larger the tank, the more supportive it’ll be to life in your aquaponics system.
Consider Available Space When Choosing a Tank
One of the marvels of aquaponics systems is that they can thrive just about anywhere provided there’s enough space. You can create a healthy system outside in your backyard, in a greenhouse environment, or even in your living room. Choose a larger or smaller tank depending on the amount of room you will have available for your aquaponics system.
When deciding where to start your aquaponics system, it’s also important to consider the plants you’re growing and the climate they’ll need to survive. If growing outside, make sure your plants of choice align with the temperature and amount of sunlight that’ll be available to them.
These factors may influence the location you choose for your system, which could in turn influence the size of the tank you will need to acquire. Consider all of these elements before choosing a tank.
2. Fish-Safe Water
Water is essential to the life of both the fish and the plants within your aquaponics system. To provide your fish and plants with the best growing environment, you need to ensure that you’re filling your tank with fish-safe water.
For water to be considered fish-safe, it needs to tick the following boxes :
- It shouldn’t contain any chlorine.
- It should contain enough bacteria to break down any ammonia that’ll build up after you introduce your fish to the tank.
- It should have a neutral pH (I’ll discuss pH maintenance more in-depth later on in the article).
In addition to ensuring the water meets the above criteria, you’ll also want to allow it to cycle for at least four weeks after you fill the tank. This extended cycling period allows for beneficial bacteria to begin to grow and ensures that the pH will stay at a relatively stable level.
As you might have gathered from previous sections, fish is one of the most critical components of an aquaponics system. Fish waste serves as a natural fertilizer for the plants in an aquaponics system because it contains essential nutrients that help keep the plants healthy.
To be specific, fish excrement contains nitrogen.
Nitrogen is an essential nutrient for plant growth because it plays a vital role in the process of photosynthesis. So when plants get plenty of it, they grow bigger and stronger because they’re better equipped to create energy.
Fish waste also packs potassium and phosphorus, two more crucial elements for plant growth.
Potassium adds resistance against disease and supports the healthy function of the cells that make up the plants’ structure. Phosphorus, on the other hand, aids in the healthy development of plants, especially throughout the earlier stages of growth.
Fish waste is typically dispersed through water. The water is usually recycled within the system, consistently supplying the plants with essential nutrients.
Here’s a YouTube video on how that works:
How to Choose Fish For Your Aquaponics System
The type of fish you choose for your aquaponics system is more important than you might think. When making that choice, pay attention to the waste production and the reproductive qualities of each fish breed.
If you don’t have any specific fish breeds in mind, consider tilapia, goldfish, and Koi.
Tilapia is an excellent option for anyone hoping to eat the fish they grow in their aquaponic system. This type of fish is a versatile ingredient for various meals and an excellent source of protein. What’s more, it only takes about ten months of adequate care for tilapia to grow large enough to harvest and eat!
If you can’t readily find tilapia, goldfish can be an option. These fish species reproduce reasonably quickly, making them a fantastic option for aquaponic systems. They’re particularly an ideal choice if you prefer not to eat the fish.
Koi can also be an intriguing option if you want to create an aquaponics system but don’t plan to eat the fish you grow. Some people grow this breed in their systems and then sell the fish once they reach a specific size for a profit.
How to Determine the Ideal Stocking Density
Take special care to avoid overcrowding your tanks because doing that can take a toll on your fish’s health. When stocking your tanks, aim for approximately 20 fish for every 0.13 gallons (500 mL) of plant bed media. Keep in mind that this stocking ratio recommendation applies to fully-grown fish.
If you’re stocking your tank with young fish, you can use a lower fish-media ratio. Using a relatively low ratio will help keep the dissolved oxygen levels in your tank optimal for fish health.
Here’s a YouTube video that explains aquaponics stocking density in greater detail:
4. Fish Food
Fish need to eat to create waste and play their part in the aquaponics cycle. As such, fish food is a crucial ingredient for your aquaponics system. In fact, it’s the only aquaponics system input that needs regular replenishing.
The type of fish food you choose will depend on the kind of fish you have in your system. So when choosing fish for this purpose, you’ll want to learn about the type of food they’ll require. Ideally, you should choose a fish species that’s not too selective with its food requirements.
5. A Media Bed Container
The media bed setup is one of the easiest, most popular methods of creating an aquaponics system at home. This kind of setup requires a pump to pull water from the water tank into the plant bed. The water is then dispersed throughout the plants’ growing media, allowing them to soak up any nutrients they may need from the water.
In this type of aquaponics system, the plants need a bed—also known as a flood table—to reside. The flood table can be made of wood or firm plastic material.
Whichever material you choose, you need to ensure that the container has some drainage method. You also need to raise the container on a stand strong enough to support the weight of the plants and the growing media as they’re suspended above the water tank.
Note that creating an aquaponics system without a media bed is also possible through the deep water culture setup and the nutrient film setups.
These alternative methods involve submerging plant roots into the water tank itself such that they draw water and nutrients straight from the water. This is different from a media bed system, where the water is circulated through a system or pump between the tank and the growing bed.
6. A Growing Media
Cinder rock is the standard growing media for plants in a media bed setup. Cinder is a type of lava rock that makes an excellent media choice due to its natural porosity, which allows water to circulate through the plants’ growing environment effectively.
Cinder’s porosity and high surface area allow for water filtration. Thorough filtration means that once the water fully circulates through the plant bed, it can be returned to the fish tank as fresh water for the fish to thrive in.
Clay pebbles are also great growing media for aquaponics systems. These are appreciated for their water retention, which helps ensure that plants get the hydration and nutrients they need.
Plants are a must-have for an aquaponics system. Including plants creates a natural ecosystem where plants and aquatic life benefit from each other. The plants you grow in your aquaponics system can also serve as a food source for you and your family.
There are a couple of things you’ll need to do to keep your plants healthy.
First off, you’ll need to keep the water condition healthy for plants. There isn’t much you need to do to ensure that besides keeping enough fish to support the plant’s nutrient requirements and staying on schedule with routine maintenance.
Note that plants with higher nutrient demands require a thoroughly built and stocked aquaponics system. That’s why peppers, tomatoes, and most ornamental flowers aren’t recommended for aquaponics beginners. You might want to avoid these until you have a well-established aquaponics system, at which point you’re free to experiment with different plant species.
Secondly, you’ll need to pay attention to your specific plants’ sunlight and temperature requirements.
To help you figure that out, let’s look at some of the most common plants for aquaponics and what they need to thrive.
Lettuce is a common plant used in aquaponics systems. Leafy lettuces thrive in aquaponic setups and are a fantastic choice for beginners looking to start a system of their own. These plants thrive in consistent moisture, making them perfect candidates for an aquaponic system.
As far as species-specific growth requirements go, lettuce needs plenty of sunlight. It also requires cooler temperatures between 45 and 80 °F (7 and 27 °C).
Herbs are also great options for your aquaponics setup, mainly due to their versatility. Hardy herbs like basil and chives are typically successful in this growing environment. Rosemary is another great choice.
Most herbs appreciate a growing environment with six or more hours of sunlight each day. Temperature requirements vary for the different types of herbs, so be sure to look into the specific needs of any herbs you wish to plant.
Many owners of aquaponic arrangements appreciate the versatility of fresh-grown herbs, especially when it comes to cooking.
Other Noteworthy Mentions
Other plants known for their success in aquaponics systems include strawberries, kale, chard, and root vegetables. Strawberries and chard typically require full sun (at least 6 hours a day) for optimal growth, while kale and most root vegetables prefer at least a few hours in the shade each day.
All of these plants are known to grow successfully in temperatures ranging from 60 to 80 °F (15 to 27 °C).
8. A Waste Filtration System
As I previously explained, the waste produced by fish is recycled through an aquaponic system and used as fertilizer for your plants. However, you don’t want waste solids to be dispensed into your grow beds.
Instead, only liquified fish waste should be distributed throughout the grow beds. Waste in liquid form makes it easier for your plants to absorb the nutrients, naturally filtering the fluid before it returns to the fish tank.
To ensure that no waste solids enter the grow beds, many responsible aquaponic systems owners place simple screens at the mouth of their water dispensers. Placing such a screen where water enters the grow bed allows you to filter out any solid waste before it gets carried into the next stage of the system.
9. An Effective Drainage System
A drainage system allows water to flow between the fish tank and the plant beds. There are two ways to set up the drainage system.
The first method involves flooding the media bed with water and then letting the fluid drain into the tank, while the second involves consistently circulating water throughout the media bed.
The type of drainage system you choose depends on the kind of plants you plan to grow. Understanding your plants’ oxygen and watering needs can make a massive difference in aquaponic systems and the draining method you choose.
To help you make the right choice, let’s review each type of drainage system in greater detail:
Method 1: Flood and Drain
Most plants require regular aeration to grow most successfully. Aeration occurs when the growing media is given time to dry out, allowing the plants’ roots to access more air.
Most plants don’t thrive with their roots wet at all times, and constant root submersion can lead to diseases like root rot and fungus infestation. Still, they need water for survival.
To address the plants’ water needs without “drowning” their roots, some people use a system that floods the growing beds thoroughly before draining the water fairly quickly. That, in a nutshell, is how a flood and drain system works.
To set up the system, a siphon is built into the grow bed. The siphon manages the amount of water allowed to accumulate in the grow bed. Once the water pumped into the grow bed reaches a certain level, it’s redirected and returned to the fish tank.
The purpose of the siphon is to create the suction required to manage this flow of water back into the tank more efficiently. In doing that, it ensures that the plants’ roots are never exposed to a large amount of still water for extended periods.
Method 2: Constant Circulation
Consistently circulating water through your media bed works particularly well with water-loving plants like lettuce. That’s because lettuce and other similar plants tend to thrive when their roots have plenty of access to fresh water.
So, naturally, you’ll want to use the constant circulation drainage method if you plan on primarily planting lettuce and other similar plants.
10. Consistent Maintenance
Aquaponic systems are relatively independent ecosystems. However, you should never ignore them completely. It’s crucial that you devote time, attention, and care to the life and upkeep of the ecosystem you built.
Here are a few pointers to keep in mind as far as maintenance goes:
Be Careful Not to Overfeed Fish
One of your most crucial responsibilities as an owner of an aquaponics system is feeding your fish regularly. I’ve already outlined the importance of choosing the right food for your fish, so I won’t overemphasize that. Instead, I’ll focus on how often you should feed your fish.
Most experts recommend that you only feed your fish the amount of food they can consume within five minutes. If there are remnants, be sure to remove them after 30 minutes. You don’t want to have food remnants floating around because they’ll eventually rot, potentially harming both your plants and the fish.
Manage Water Quality for Healthy Fish
Make a habit of regularly checking your water for extreme pH levels and chemicals that might be harmful to your fish. Also, keep an eye on the water’s oxygen concentration, temperature, and nitrogen levels.
You can monitor oxygen levels with an oxygen meter, which tells you how many milligrams of oxygen are in each liter of water. Ideally, your aquaponic tank should consistently have a dissolved oxygen level of around 5 milligrams per liter (5 ppm).
As for the pH, you want to keep it neutral or at least close to 7.0. A neutral pH creates the optimum environment for fish and natural bacteria to thrive.
Testing pH levels is a relatively straightforward process. You can use a simple pH meter/testing kit or an electronic pH meter. The latter is often preferred for its accuracy.
If you detect a low pH, raise it by adding designated chemical solutions like aquarium buffers. Aquarium buffers are solutions formulated to add bicarbonates and sodium carbonate to the water to raise its pH to a natural level.
If high pH is a concern for your aquaponic system, one of the most effective solutions is to use sphagnum peat moss. By placing peat moss in a mesh bag and leaving it in the tank for a couple of weeks, you can naturally and safely reduce the pH in the water.
11. A Well Thought-Out Plan
Last but not least, a deliberate implementation plan is crucial to creating a successful aquaponics system. So before you even think about purchasing materials for your system, take into account a vast assortment of decisions you need to make.
Some of the most critical things you’ll want to figure out beforehand include:
- The type of plants and fish you’ll use
- The volume of your tank
- The environment you plan to plant in
- The type of media you’ll use
- The amount of available space
Failure to plan these aspects of owning an aquaponics system can derail your success. But even with all the planning and decision-making, don’t forget the most important part of setting up an aquaponics system: enjoying every bit of the process. When done correctly, the experience of fostering both plant and animal life can be surprisingly rewarding.