Comparing Aquarium Gravel To Sand – Which Is Best For Your Tank?

In this article, we’ll be comparing two substrates for your freshwater aquarium; sand and gravel.

If you’re undecided on which one to go with, we’ve provided a rundown of the pros and cons for both options and a few tips to help you choose a good substrate for your tank.

Let’s begin.

Advantages To Using Sand as Freshwater Tank Substrate 

Using sand in a freshwater aquarium isn’t as common as gravel, but it can be done, and it’s a great way to provide a very natural feel to your tank.

Most sand is inert and will not impact the water parameters like some gravel and rock can. 

Another good thing about using sand is that it compacts very easily making it easier to clean as most fish and food waste will sit on top of the sand.

However, if you are using lightly colored sand, you will notice the waste easily, and it can be a bit of an eyesore for the perfectionist. 

Lastly, sand is a great option if you have fish like the Corydoras Catfish that have barbels and eat from the substrate, using gravel might injure these fish.

If you keep snails, crabs, or other fish that like to burrow sand is the best option.

Why Sand May Not Be Best Substrate For Your Tank

While there are benefits to sand, there are also some things you should be aware of.

For example;

Some sand is very dense and will make it difficult for root feeding plants to grow. Also, sand doesn’t naturally absorb the micro/macronutrients required to sustain healthy plant growth.

If you decide to use sand and keep live plants, you’ll need to pick up some root tabs.

Sand can also be very messy if you’re not careful when cleaning.

It can easily get sucked up your gravel vacuum or worse into your filter, where it may damage your filter’s impeller.

Lastly, and likely the biggest concern if you decide to use sand is its tendency to create gas pockets known as anoxic zones, or anaerobic dead zones, which are potentially dangerous for both your fish and the plants.

aComparing Aquarium Gravel To Sand
A mixture of both can work well for some aquarium plants

Advantages To Using Gravel as Freshwater Tank Substrate 

Gravel is likely the most popular substrate used in aquariums, especially for beginners.

This is because gravel is easy to use, clean, available in almost any shape, size, and color so you can get the exact look you want.

One of the biggest benefits of using gravel is the surface area it provides.

A gravel substrate provides a great place for the beneficial bacteria to grow; it actually provides better filtration than your filter.

If using live plants, they will love those tiny spaces in between the rocks. Even the rocks themselves are suitable for growing bigger root networks, and faster at that.

Gravel can also be used to cap a nutrient-rich soil like Fluval Stratum which will promote large healthy plant growth while keeping the plants weighted and in place.

Most aquarium gravel is also inert, meaning it’s not going to affect your tank’s water chemistry.

Why Gravel May Not Be Best Substrate For Your Tank

Even though Gravel is likely the first choice for most fish keepers, it does have some drawbacks.

For one;

Bits of food and other waste can insert themselves between the rocks, requiring a more thorough cleaning with a gravel vacuum.

If you let too much waste build up in your gravel, it can significantly decrease water quality.

Additionally, some fish can pick at the gravel, hurting their mouths or barbels (if any), or worse choke on the smaller pieces.

Sand vs. Gravel: Choosing by Comparing

Sand and gravel each have their pros and cons making it an important thing to consider before setting up your aquarium. 

Here are some advantages and disadvantages while focusing on a few important points;

Fish and Plants

  • If you keep fish that like to dig in the substrate, go with sand as gravel can harm them seriously.
  • If your tank has lots of plants, gravel will help sustain their nutrition and root systems. However, a plant substrate would be best.


  • Sand can cause a mess when stirred around and damage your filters.
  • On the other hand, gravel is so much easier to clean as you can wash it, which is impossible with sand.

If you have expensive equipment with lots of moving parts, try to avoid sand.

Maintenance & Water Quality

  • Sand is excellent because waste sits on top of it, making cleaning easy.
  • Sand can create gas pockets or anaerobic dead zones.
  • Sand will need to be replaced regularly, which can be cumbersome.
  • Gravel is harder to clean but provides a great place for beneficial bacteria, ultimately keeping your water parameters more stable.

If you want less maintenance go with Gravel as your choice.

Final Recommendation

Here is a great video from Palmer Aquatics explaining why he only uses Gravel in his tanks.


Q.Can I Use Beach Sand In An Aquarium?

A. Beach sand can be used in your fish tanks however it will need to be rinsed and cleaned really well.

To clean it you’ll need to soak the sand, drain the water and rinse the sand many times to ensure it has been cleaned well enough.

Sand from the beach can contain microorganisms, salt, waste, and even chemicals and you can never be sure you’ve cleaned it good enough.

If you want to use sand it’s best to buy it from your local fish store or online.

Q. Can You Mix Sand And Gravel In A Fish Tank? 

A. Sand and gravel can be used together and it’s a great way to include different elements in your tank. Think of a beach with a mountain landscape in behind.

If you plan on mixing them completely, it’s best to put the sand down first and cap it with the gravel. If you place the gravel down first and cover it with sand, eventually the sand will settle to the bottom and your gravel will be on top. 

Q. How Often Should You Clean Aquarium Gravel?

A. It’s recommended to clean your gravel with a gravel vacuum at least every two weeks to ensure the excess build-up of waste doesn’t affect your water quality.

That said, it really depends on how many fish you keep, how often you feed them, and whether or not you have live plants.

Q. Can You Put Too Much Gravel In A Fish Tank?

A. This is difficult to answer as you can find many examples of beautiful scrapped and healthy tanks with gravel as deep as 6”.

That said, in most cases you can have too much gravel.

The deeper the substrate (Gravel or Sand) increases the chances of dangerous gas pockets forming. These are called anoxic zones, or anaerobic dead zones, which are potentially dangerous for both your fish and the plants.

This happens because the deeper substrate (at the bottom) will not get enough oxygen or water flow to help dilute harmful toxins like nitrate and ammonia. Over time these pockets can become very dangerous if disturbed.

If you plan on having a deeper substrate it’s best to use live plants and keep animals that will help stir the substrate to ensure oxygen and water flow can reach the lower levels.

For most aquariums, try to have about 1 pound of substrate per gallon as a good starting point.

Wrapping It Up

It really comes down to what you want as a fish keeper? 

Do you want plants, less maintenance, or do you want the look of an Amazonian Biotope?

Pick not only what’s right for you, but more importantly, what’s suitable for your fish and the environment you’re going to provide.

Think about your options, the fish you want to keep and make a well-informed decision.