Since you’re reading this, you might be considering venturing into the world of hydroponics — or you’re already a seasoned hydroponic grower who’s looking to try a new hydroponic medium. If so, then you’ll need to familiarize yourself with the different hydroponic media types that are available. In this post, we’ll take a look at some of the most popular types of growing media and help you decide which one is right for you. 


Hydroponic growing media is any material that can be used to support plant growth in a hydroponic system. Hydroponic medium can be anything from small rocks and pebbles to crushed coconut shells or expanded clay pellets. The main purpose of hydroponic growing media is to provide a stable foundation for the plants’ roots, as well as to help with the uptake of nutrients. 

While there are many different types of growing media, they all share one common goal: to provide a suitable environment for plant growth. The type of media you choose will depend on several factors, including the hydroponic system you’re using and the plants you’re growing. 

Now that we’ve answered the question “what is hydroponic growing media,” let’s take a look at some of the most popular options. 


Hydroponic growing media is different for everyone and every hydroponic gardening system. It all depends on the hydroponic system you are using and what your goals are. Therefore, what might work well for a drip system, might not work as well in a nutrient film technique system.

Some common hydroponic grow media types are: 


Air, a soilless media, is an often overlooked type of hydroponic media, but it can be used to support plant growth. Plants grown in air have a big advantage in that their root system can get access to plenty of oxygen (which is essential for healthy plant growth). The main downside to growing plants in the air is that they will require regular misting or watering to prevent them from drying out. If you have a grow tent or other controlled environment, air might be the best media for you.


Air stones are a type of air media that is becoming increasingly popular. These stones are made from a variety of materials, but they all serve the same purpose: to aerate the water in your hydroponic system. The stones are placed in the reservoir and connected to an air pump, which provides a steady stream of bubbles. The bubbles help to oxygenate the water and keep the roots of the plants healthy. 


Coconut coir is a popular hydroponic growing media that is made from the coconut fiber material between the outer shell and the inner flesh of a coconut. It is an environmentally friendly option that is also renewable, making it a great choice for those looking for a sustainable option. Coconut coir has excellent water retention properties and is also very easy to work with.

Ground-up coco coir is an excellent hormone-rich, fungus-free soil for plants. It helps the seeds and seedlings in beginning strong in the same manner that it assists coconut germination. The coir increases the water holding capacity of soil up to twenty times and helps keep the pH of the soil near neutral. There is even organic coco coir, such as Coirganic Coco, from Char Coir

Such a hydroponic grow medium is a great alternative to peat moss, which is harvested from natural environments and can take years to regenerate.


Expanded clay aggregate pellets are made from a type of clay pebbles that have been heated until it expands. This creates small, round pellets that have a high porosity and can hold a large amount of water. They are also lightweight and non-toxic, making them a popular choice for those looking for an environmentally friendly option. 

The most appealing aspect of them is that they have low nutrient content and are balanced in terms of pH. Additionally, because of their spherical form and porousness, they help to maintain an ideal oxygen/water balance, avoiding overly drying or drowning the roots. 

This is ideal for a growing plant system that is just starting out. The lightweight expanded clay pellets will not interfere with the delicate balance that you are trying to achieve and provide a stable environment for your hydroponics system. So, if you’re working with a deep water culture system expanded clay pellets might be the best media for you.


Gravel is a popular choice for those looking for an affordable and easy-to-use hydro media option. It is a great choice for those who are new to hydroponics, as it is easy to work with and requires little maintenance. However, gravel has a low water retention rate and can be difficult to clean, making it less ideal for those looking for a low-maintenance option. 


An alternative to gravel is Arqlite Smart Gravel. It is a pH neutral growing medium made from 100% recycled plastic. Unlike standard gravel, it is pre-cleaned, doesn’t deteriorate, and is dust-free. It weighs half as much as expanded clay, and can be reused over and over, unlike rockwool. It also creates a healthy environment for good bacteria.  


Perlite is a type of volcanic glass that has been heated until it expands. It is lightweight and has a high-water retention rate, making it a popular choice for those looking for an easy-to-use option. Perlite is also sterile, meaning it is less likely to harbor diseases or pests. 

This growing medium is best for systems such as the wick system, where the roots are not in direct contact with the nutrient solution. Perlite can also be mixed with other growing media to create a custom mix that meets your specific needs.


Vermiculite is a type of mica that has been heated until it expands. It is like perlite in that it is lightweight and has a high water retention rate. However, vermiculite also contains nutrients that can be beneficial to plants, making it a popular choice for those looking for a complete growing solution. 


Oasis cubes are made from compressed expanded polystyrene (EPS), a kind of growing media. The floral foam used to make oasis cubes is shaped like a sheet. Each cell in the medium’s individual cell contains all of the essential elements for plant growth, including air and water. 

Oasis cubes are primarily of use to growers as a starting environment for seedlings or cutting. The medium is pH neutral. Its cells absorb water and air readily, which is very important for seeds or cuttings because it allows them to grow and expand easily within the open cell structure of the medium. Furthermore, roots may easily develop and flourish in this type of hydroponic growing medium. Oasis cubes also have the ability to release water and air slowly, which is ideal for plants that are in a transition period. 


Rice hulls are the outer shells of rice grains. They are a by-product of the milling process and are often of use as a source of fuel or animal feed. However, they can also be a hydroponic growing medium. 

Rice hulls have a high porosity, which allows them to hold a large amount of water. Additionally, they are lightweight and easy to work with. 

The drawback of utilizing rice hull media is that they deteriorate over time, thus you must replace them on a regular basis or risk harming plant root systems. Because the hulls aren’t treated, there’s also a chance they’ll introduce microorganisms or weed seeds into your garden. 


Pumice is a type of volcanic glass that has been heated until it expands. It is similar to perlite in that it is lightweight and has a high water retention rate, but pumice also contains nutrients that can benefit plants. 

One of the benefits of using pumice as a growing medium is that it helps to control moisture levels. Additionally, pumice is a natural insulator, which can help regulate your garden’s temperature. 


Growstones are made from glass waste that has been melted and reformed. Like perlite, they are lightweight and have a high water retention rate. However, growstones also contain a large amount of surface area, which allows them to hold more nutrients and oxygen than other growing media. 


Sawdust is a by-product of the lumber industry. It is composed of small pieces of wood that are left over from the sawing process. Sawdust can be used as a growing medium, but it must be treated before it is added to your garden. 

The primary benefit of using sawdust as a growing medium is that it is cheap and easy to find. Additionally, it is lightweight and has a high water retention rate. However, sawdust also contains a large amount of organic material, which can be beneficial to plant growth. Unfortunately, sawdust can also harbor pests and diseases, so it must be treated with an insecticide or fungicide before use. 


Wood chips are an excellent mulch for your garden. They help to keep the moisture in the soil and prevent weeds from growing. In addition, they add organic matter to the soil, which helps to improve its texture and drainage. Wood chips can be of use in any type of garden, but they are especially beneficial for vegetable gardens for hydroponic crops. 

If you are using wood chips as a mulch, it is important to choose the right type of wood. Hardwood chips are best for gardens, as they break down slowly and provide nutrients to the soil over time. Softwood chips, on the other hand, will decompose quickly and should be used sparingly. Pine needles and cedar shavings are also good choices for mulching, as they add acidity to the soil and help to discourage weed growth. 


Peat moss is a type of sphagnum moss that is found in bogs and wetlands. It is partially decomposed plant matter, which makes it an excellent source of nutrients for plants. It is also very absorbent, making it ideal for use in potting mix or as a mulch. 

This type of growing media is beneficial to plant growth because it helps to aerate the soil and improve drainage. The peat moss adds organic matter to the soil, helping to retain moisture and promote plant health. Peat moss can soak wet, then quickly rehydrate, minimizing compaction and durability concerns. These extend the material’s life cycle by several years of usage. 

Furthermore, this medium does not include harmful weed seeds or organisms, unlike other organic composts. To improve aeration and alter the PH of the medium, add peat moss, perlite, vermiculite, or Styrofoam particles. 


Sand is another popular choice for hydroponic growing media, as it is readily available and relatively inexpensive. It has a high water retention rate and is easy to work with but can be difficult to clean and may require more maintenance than other options. 

One of the benefits of using sand as a growing medium is that it helps to anchor plants in place. Additionally, it can be used to adjust the pH level of your garden. However, sand does not retain moisture very well, so it must be supplemented with other materials. 


Mineral wool is a type of man-made fiber that is made from melted minerals. It is commonly used as insulation but can also be used as a growing medium. Mineral wool has a high water retention rate and is very easy to work with. However, it can be difficult to clean and may require more maintenance than other options. 


Rock wool is a sterile and porous material made from heated rocks. These rocks are spun into thin fibers, which are then compressed into cubes or bricks. Many advantages of growing with wool include its resistance to insects, moisture retention, and excellent air and water retention. This protects your plants from drying out while providing plant roots with ample oxygen. Another great thing about wool is that it provides an ideal growing environment for beneficial bacteria, which can help to improve plant health. 


VidaWool is a type of synthetic fiber made from recycled materials. It is similar to mineral wool in terms of water retention and ease of use. However, VidaWool is more environmentally friendly and easier to clean than other options. 

VidaWool is an excellent choice for those looking for a sustainable and environmentally friendly growing medium. 


Starter plugs are made from various materials, including peat moss, coir, and perlite. They are small blocks that are designed to be used as a starting environment for seedlings or cuttings. Starter plugs have a high water retention rate and can absorb and release moisture quickly, making them ideal for those who are new to hydroponics. 

Additionally, many starter plugs come pre-treated with a variety of nutrients, making them a complete growing nutrient solution. 


In some circumstances, a mixture of media is used. For example, coco coir brand Char Coir, in addition to providing a high quality Coco Coir product, also has a product called Cloud Coir, which is a 50-50 mix of coco coir and perlite. This means that it has all the hydroponic benefits of coco coir “Cloud Coir is the perfect ratio for roots to thrive and not become over saturated allowing for better nutrient uptake more frequently,” the product details explain. 


So, what is the best hydroponic growing medium when you compare all types of growing media?

The answer to that question depends on your specific needs and preferences. What we can say definitively, however, is that there are a variety of different growing media options available to you, each with its own set of benefits and drawbacks. Do some research, experiment a little, and find the option that works best for you! 

However, no matter which hydroponic medium you choose, it’s important to make sure that it is of high quality and suitable for your needs. At HRG, we only carry the best products from trusted brands, so you can rest assured that you’re getting the best possible value for your money. Find our brands with our store locator. Happy growing! 

Back to blog