Aquaponics Grow Media (How To Choose The Best)

We may earn compensation from the products mentioned in this post. See our Affiliate Disclaimer.

One of the major components that distinguish Aquaponics from traditional soil-based gardening is how the system utilizes grow media. Instead of soil, growers use various media, or cultivation platform, which is composed of materials that can facilitate fruit and vegetative growth in a 100% soilless environment. With that said, choosing the right Aquaponics grow media for your crops is an essential part of the pre-planning process if you are thinking about starting your own aquaponics operation.

If you are totally new to aquaponics, it’s critical that you understand the functions that aquaponics grow media provides, the factors to consider when choosing aquaponics grow media, and some of the most common grow media used by aquaponics practitioners today. In this article, we will explore each of these topics, and others, in detail.

What is Aquaponics Grow Media?

Aquaponics grow media is a soilless natural or synthetic material that functions as a support body for your crops in the system. Like soil, it is a component that protects and ensures plant roots are anchored in the right position and allows seeds to germinate safely within the material, instead of in the ground like in traditional gardening. The grow media likewise helps plants soak in the required nutrients and keep them from toppling over due to severe weather. 

Moreover, they act as a surface area for the necessary bacteria that are vital in your Aquaponics system. Aquaponics grow media is a foundational component of this type of gardening, thus, before planning your system, consider spending time researching all of your options.. Take note, though, that not all Aquaponics methods, like Deep Water Culture Aquaponics, require the use of growing media.

Factors in Choosing your Aquaponics Grow Media 

There are a myriad of options you can choose from, and while many growers use non-organic material, others prefer using organic grow media. Now that you know the functions that grow media provides, let’s take a look at the factors you need to consider when choosing the suitable grow media for your system.

PH Neutral

As you may know, part of the Aquaponics System Maintenance Checklist is to monitor and maintain the ideal pH range. When choosing your grow media, remember that some material can affect the pH level of the system, which can delay plant development or even hurt your fish. Opting for a material that is pH neutral will allow you to better manage the pH scale of your Aquaponics system.

Safe for your hands

Because you will be handling the grow media with your hands, when you place them in their grow beds, it is essential to choose safe materials for your hands. Choose a material that you can easily work with and will not injure your hands. 

Weight

Weight becomes an increasingly important factor, particularly on smaller or flimsy aquaponics bed setups. When choosing an optimal media, see to it that you choose a material that is not too bulky and heavy that you’ll have difficulty in managing it or one that could physically collapse the support structures of your garden bed. 

Keep in mind that larger setups are inherently heavier, thus, consider a media that is light to medium weight to make sure the weight is evenly distributed across the bed. Lastly, depending on how coarse the media is, it could become problematic in clogging up the pipes in your system.

Cost

If you are only starting out in Aquaponics, the price of the grow media is something that you should also consider. Some materials can be costly, while others tend to be economical. It is better to examine your budget first then choose the grow media that is within your resources.

Best Grow Media for Aquaponics

Now that you are aware of the factors to consider in choosing your grow media let’s examine some of the best grow media for Aquaponics. Please take note that while these materials are your best options, there is no such thing as a perfect medium, and the below materials have their own pros and cons. Here are some of the best and most common grow media:

• Lava Rock
• Clay Pebbles
• Expanded Shale

We will discuss each specific item in detail in the following sections.

Grow Media Lava Rock

If you are searching for a grow media with plenty of surface area, then consider lava rocks. These types of rock form when hot lava rapidly cools down. They contain air pockets inside, which would mean an additional surface area for bacteria. Aside from this, lava rocks are typically pH neutral, lightweight, and they offer good drainage. 

While lots of growers use lava rock, these types of media do have some downside to them. Lava rocks usually have sharp edges that can likely cut your hands when you handle them, plus cause some harm to the root system of your crops. Remember before using lava rocks soak them in water for a few days to prepare them for thorough cleaning. Consider using a water spray with sufficient pressure when you rinse them to get rid of contaminants that can harm your fish and crops. 

Grow Media Clay Pebbles

Another grow media that will offer you plenty of surface area are clay pebbles. They are also known as expanded clay or Hydroton. While there are some grow media that are only suitable for specific plants, you will be glad to know that clay pebbles are compatible with many types of plants. When you look closely at clay pebbles, you will notice that they contain many tiny holes. These permit both the material to hold sufficient water plus allow drainage. Aside from that, these holes promote good airflow. 

Similar to lava rocks, clay pebbles are pH neutral. However, while the material is one of your best options, know that clay pebbles can be expensive. Also, it’s common to see during their first use that the pebbles may float, which can cause an obstruction in your system. 

Grow Media Expanded Shale

Expanded shale is pH neutral, and is created as a by-product of the silicon-based shale being crushed and heated to high temperatures. Similar to lava rock, expanded shale contains air pockets that produce additional surface area for bacteria. And because the material underwent a heating process, you will find their edges a bit polished. Hence, they are easier to manage and will not damage plant roots. 

A benefit of using expanded shale in your setup is that the material is reusable and is typically more affordable than other types of growing media. However, while expanded shale is also porous yet lightweight, it can be heavier than clay pebbles.

Other Aquaponics Grow Media Options

As mentioned before, some growers prefer to use organic grow media. An example of this is Coconut Coir. One of the benefits of using Coconut Coir is that it has great water retention capabilities. Due to this, the likelihood of your crops becoming dehydrated is greatly reduced. Coconut Coir is also environmentally safe and highly reusable. 

On the one hand, though, know that Coconut Coir can likewise carry too much moisture which can be a drawback for your plants. Also, when using this grow media, make sure to monitor the pH level since it may fluctuate.

Conclusion: Which Aquaponics Grow Media Is Best For You?

With Aquaponics gaining much attention, more and more people are now using grow media in their system. Bear in mind the factors you need to consider when choosing the right grow media for you. Again, when picking the wrong material, you may end up delaying your plant growth or potentially harming your fish.  

It would be best to make sure the one you choose carries the ideal properties suitable for you and your Aquaponics system. If money is not an issue, your best option is to use clay pebbles which is also favorable if you’re planning to grow different types of crops. Otherwise, if you’re working on a tight budget then opt for expanded shale or lava rocks.