Aquaponics systems commonly involve raising freshwater fish because they can tolerate diverse water temperatures and pH…
We may earn compensation from the products mentioned in this post. See our Affiliate Disclaimer.
As more people begin to see the importance of having the ability to grow their own food, aquaponics has quickly become one of the most popular forms of gardening because of its seamless ability to cultivate crops and raise fish simultaneously. However, getting started in aquaponics can be challenging if you don’t know where to begin. Choosing the right system type upfront is critical if you want to avoid regrets or additional costs to change methods down the road. Regardless if you are a beginner or a savvy veteran, using a media bed aquaponics setup can be a great choice.
The Media Bed system is the most popular of all aquaponics growing techniques because the basic design is straightforward, it typically has lower startup costs than other methods, and DIY building materials are easy to find. In this article, we will examine the benefits and drawbacks of using Media Bed Aquaponics and help you determine if this method is the right one for you.
What is Media Bed Aquaponics?
The Media Bed aquaponics method is a soilless form of gardening that leverages four primary components: fish, grow beds, grow media and plants. These parts work together to form a closed-loop system that consists of continuous end-to-end nutrient flow and waste-filtering. The grow bed is a container that holds the grow media, including materials such as volcanic gravel or clay pebbles.
The purpose of using grow media is to anchor and support the plant’s roots while also acting as a natural biological filter for all of the water flowing through the system. The fish are housed in separate tanks, and their leftover waste is pumped to the grow beds to provide vital nutrients to the plants.
How Do Media Bed Aquaponics Systems Work?
The Media Bed method is one of the most popular choices among aquaponics practitioners because the design is relatively straightforward, which makes it easier to manage. Let’s take a look at each of the components of a Media Bed system in detail and discuss their functions:
The Role of Fish in Aquaponics
Fish are the lifeblood of any aquaponics system, and it’s their poop and urine left in the water that produces the nutrients needed to kickstart the entire growing process. Over time, considerable amounts of waste build up in the fish tank. Under normal circumstances, this waste would need to be removed through a traditional tank filter, or else it would become toxic to the fish. However, in the case of Media Beds, the water is instead pumped out of the tanks through a hose directly into the grow bed, where it will “flood” the structure with the nutrient-rich water.
The plant roots, which live within the grow media, now have direct access to the water and can feed on the nutrients in order to grow. But how exactly does this all happen? Behind the scenes, there is a biological nitrogen conversion process that begins inside the fish. Below is a video to help you understand the interesting science of this process more in-depth.
The Role of a Grow Bed
The grow bed is the container or structure that will provide the base for the plants to grow. The bed’s width and depth will determine the number of plants and the amount of growing media and water the garden can support. Beds will contain built-in mechanisms such as piping, bell-siphons, and drains to regulate water flow through the entire grow bed.
The Role of Grow Media
Grow media are materials used to support plant roots, provide aeration, allow better nutrient absorption, and act as a biological filter. Once the water from the fish tanks reaches the grow bed, the media inside such as lava rocks or gravel prevents solid waste or other organisms from being reintroduced back into the fish tanks by filtering them out.
Grow Media Options for Aquaponics
One of the benefits of Media Bed aquaponics is flexibility in choosing different physical media types to use in your grow bed. However, when analyzing material options, there are some criteria that you should look for to increase your chances of having a successful garden. They are the following:
- Has a neutral pH value
- Maintains a sizeable surface area to allow bacterial growth
- Does not absorb toxic chemicals to avoid altering water quality
- Simple to handle so growers will not have issues
- Lightweight so as not to add more load in the grow bed
- Excellent drainage qualities to prevent system clogging and aeration
In addition, you may want to consider the durability of the materials, as some are just inherently more sturdy than others over the long-term. In the next section, we will examine some of the common types of media.
Among media choices, one of the most popular is Volcanic Gravel because finding the material in stores or online is easy and the material is relatively cheap. Volcanic Gravel is known to have a high surface area to volume ratio, which allows sufficient area for vital bacteria to settle.
Light Expanded Clay Aggregate (LECA)
LECA, otherwise known as expanded clay, is a versatile material that has many different applications including everything from construction to landscaping. However, it has become a great option as an aquaponics grow media because of its drainage, water retention, aeration, and insulative properties.
Other Media Options
In case the two mentioned materials are not available in your location, there are also other options such as coconut fiber, sawdust, pumice, rice hull, etc. Keep in mind that while some of these alternatives can have lower upfront costs, some can deteriorate more rapidly than others. When this happens, you must replace the media from your system more frequently.
Benefits of Media Bed Aquaponics
Typically, the media bed design is optimal for small-scale and DIY operators who don’t plan to expand their growing operations past a certain point or have limitations on available space to operate. However, there are other tremendous benefits of choosing a media bed as your first aquaponics deployment: Let’s take a look at some of the best:
Minimal Upfront Costs
The Media Bed method, with its simple design, is ideal for cost-conscious beginners. Many of the materials required to start a system are often found right in a person’s own home or garage. Also, the long-term cost of ownership is relatively low for maintaining the system itself, only needing to invest in small things such as replacement parts, fish food, and ecosystem specific necessities. However, the cost for utilities such as electricity can vary, so make sure to adjust and monitor settings on things like sump pumps or water-heaters to make sure you don’t overspend.
Diversity of Supported Plants
One of the prime benefits of Media bed aquaponics is that it supports a wide variety of plants. If you are just starting out with aquaponics and don’t quite know your long-term plan for the types of plants you want to grow, beginning with a media bed provides a wide net of options available to you.
Allows Use of Recycled Materials
Another benefit of the Media bed Aquaponics is that it allows the use of recycled materials. You will see operators install “do-it-yourself” (DIY) media beds such as plastic containers, old bathtubs, or second-hand fiberglass frames. If you decide to build your own DIY grow bed here are some things to consider when choosing your materials:
- Stable enough to carry water and grow media without splitting
- Can handle rough weather conditions if the unit will be placed outdoors
- Food grade material to protect plants, fish, and bacteria
- Simple enough to integrate with other DIY components
Can Support Heavy Plant Loads
Depending on the type of plant being cultivated, they can become quite heavy over time, which puts a lot of force on the structure of the bed itself. Because the system is usually built entirely on the ground or on top of a foundation directly supported by the ground, media bed gardens have more substantial base that allows you to grow more massive crops, such as fruit-bearing trees.
If you scour across YouTube, you will see a ton of different great examples of how practitioners engineered their media bed aquaponics systems. Many people started with 100% items found around their homes and built a functioning and thriving aquaponics setup, as seen in the video below:
Is Media Bed Aquaponics For You?
If you are just getting into aquaponics and aren’t sure of your long-term plans for the garden, using the media bed technique is a great place to start. Its simple design, low startup cost, and overall flexibility to grow many different crops make it a fan favorite amongst new practitioners. This closed-loop system is mostly autonomous, with only general environmental maintenance and care to keep it going. Many new practitioners start their aquaponics careers with a single media bed, and ten years later, they have never regretted the decision.