Hydroponic Medium Gravel

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Last Updated on October 30, 2022

Hydroponic grow medium is important to support our plants and there are various options to choose from. Gravel is another nice medium to use so, giving hydroponic medium gravel a trial won’t hurt.

Grow media helps hydroponic plants with good anchor, water draining and retention, regular transportation of air and nutrients, and a host of other great things.

Gravel is a type of medium that is locally available and easily accessible to use as a growing medium in your hydroponic garden. It would interest you to know that they were one of the very first mediums to be used in hydroponic growing.

In this guide, we will be discussing the benefits of using hydroponic medium gravel in your garden as well as a few downsides you may find using them. We will also be discussing hydroponic sand and more. So, let’s get right into it.

Hydroponic Gravel

There are different grow mediums to use in the hydroponic garden and these grow mediums must attain some specific satisfactory characteristics to make a great medium. These characteristics include chemically inert, offer adequate air circulation, and great water retention as well as good draining features.

Hydroponic medium gravel offers most of these great features. Although there are a few downsides to them, they are just not so serious and you can work your way around them.

Hydroponic Sand

Even though our knowledge of hydroponics garden means a soil-free garden: however, sand is one type of grow medium that can be used.

Sand is very cheap and easy to get because they occur in nature. However, sand is pretty heavy to use and it will require once in a while sterilization to prevent non-beneficial microorganisms from breeding. Also, the water retention of sand is not so great compared to other types of growing media. At the same time, the nutrient solution may not hold so well. This is greatly caused by their small size which has reduced their surface area.

Both sand and gravel have similar properties, but most people end up going with gravel as they offer better function.

Sand and gravel are so easy to come by and a lot of hydroponic growers may overlook these fine materials as a growing medium. They will both offer good benefits to your hydroponic garden and can be a starter media. However, they may not work for everyone in all situations.

Advantages Of Gravel Hydroponics

1.    Water Draining & Aeration

Hydroponic medium gravel offers great features such as water draining and good air circulation which make them great to use in your hydroponic garden. It is nearly impossible to overwater with gravel because of its great draining properties.

Water Draining & Aeration

However, they don’t have the ability to trap water because of their high draining feature. Thus, you will have to keep up with getting a good irrigation system that will deliver water to your plant root.

2.    Accessible

Gravel can be found in nature laying anywhere around you, thus making them very accessible.

3.    Cost-effective

Just as they are easily accessible, they are also cost-effective. Even if you don’t find them in nature anywhere around you, you can easily purchase them at a low cost. So, if you’re short of cash, gravel is a good option to go for.

4.    Easy To Clean

Cleaning your gravel before use is important and the good thing is that it’s very easy to clean.

5.    Surface Area

The surface area of gravel is great which creates contact with the roots. This encourages optimal water and nutrient absorption. However, you need to ensure the surface area is smooth with no sharp edges. This is to prevent injury to the root of your plants from friction especially when you move your container. Therefore, always go for the polished gravel rather than the sharp ones.

Organic Expanded Clay Pebbles Grow Media for Hydroponics, Aquaponics, Aquaculture Garden

6.    Reusable

Another good advantage of gravel is that it can be reused. Thus, you enjoy long-lasting use. All you need do is to take them out of your grow bed and spread out the gravel after each use for them to dry out. Also, wash and rinse them thoroughly and remove any dead roots and debris. Then you put them back into your grow bed as they are ready to be reused.

Disadvantages Of Hydroponic Medium Gravel

Below are some downsides to using hydroponic medium gravel in your hydroponic garden:

  • Weight Issues: The weight of gravel is one of their main drawbacks. Their weight might hinder you if like to move your growing plants. Also, your plant beds must be strong enough to hold their weight especially if they have to be raised above ground level.

  • Needs To Be Sashed: Pure gravel may come with a lot of dirt or particles. Thus, they need to be washed to prevent these particles from clogging your system.

  • PH Imbalance: Gravel may cause pH imbalance because it may react with the water solution. Depending on the type of parent material of your gravel, some of this gravel rock can increase the pH level. This may cause plants’ inability to take in nutrients because each nutrient requires a particular pH range for adequate nutrient uptake. Thus, this can cause a nutrient lockout. You will need to always monitor the pH and adjust accordingly to get on top of the situation.

  • Plant Root Drying Out: Because of their high draining properties, they have that much ability to hold water. Thus. Your plants may dry out quickly. You can resolve this by setting up a good irrigation system that will always keep your plant moist.

pH imbalance


Can you use gravel for hydroponics?

Yes, gravel is a good substrate to grow in hydroponics, especially for houseplants.
Gravel provides a lot of surface area for roots to grow on. In addition, the spaces between the rocks provide aeration and allow water to drain away. Gravel is not as good for growing tomatoes or other crops that require a lot of nutrients, but it is suitable for houseplants.
Small rocks are often used as a substrate for growing hydroponically, and large rocks can also be used. As long as they are not too large, they will work just fine. You may need to add some type of fertilizer to the substrate. The best substrate for growing is a mixture of sand and pebbles. I have heard of people using gravel for their indoor gardens, but I don't know if they use small stones or large ones.

What rocks are used for hydroponics?

For hydroponic growing, rocks of varying sizes are used. The size and shape of the rock affects the absorption of water by the rock. In general, smaller rocks absorb more water than larger ones, but that is not always the case. The most common types of rocks used are granite, slate, marble, and basalt. 

It depends on the type of rock you use and what you are growing in the system. For example, the absorption rate of the rock will vary depending on its size.
If you use a small rock for a hydroponic system, you should choose one that is dense enough to prevent the nutrients from leaking out. If you use a large rock, you should choose one that is porous enough to allow the nutrients to penetrate the rock. If you are using a hydroponic system in an aquarium or fish tank, then the rock should be fine, because the water level in the aquarium or tank is usually at or near the surface. However, if you are using a hydroponic system in a bucket or other vessel, then the rock should be large enough to prevent the nutrient solution from spilling over the top.

Can I use river rocks in hydroponics?

You can use river rock as a substrate for your plants. They may not be the best option, but it's worth a try. If you don't have enough space to grow your plants in a larger container, then river rock will do the job. You can use it to make a grow bed. A substrate is something that plants grow on and absorb nutrients from. The two main substrates are sand or peat moss.
These two substrates are often used with hydroponics because they allow water to easily flow through. River rock is not a good substrate for hydroponic use. It has small holes and cracks, which could hold water. It could also cause problems with the nutrients flowing into the plant. Another issue is that if you use river rock, you might find that you need to change your pH level more often than you would with sand or peat moss.
You should consider the following points when using river rock in a hydroponic garden: You should make sure that the river rock is not contaminated with heavy metals and other pollutants, as these can cause health problems. You should also make sure that the river rock has a good drainage system.

Hydroponic Medium Gravel: Final Say

We can see that using gravel as a medium in your hydroponics garden is not so bad. Even though gravel may not be one of the best grow mediums to use in your hydroponic garden, it can still serve some good purposes.

Both sand and gravel can be used as a growing medium. However, most hydroponic growers will go with gravel as they are more reliable.

So, that’s what we have on hydroponic medium gravel and we hope you’ve learned two or more things. Happy growing!

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