Which Is Better Sand Or Gravel For A Fish Tank?

Having a fish tank is not an easy thing to achieve, let alone maintain. There are so many factors that need to be considered, and one of these things is the substrate.

There are several choices for aquarium substrate, and the most common and popular choices are sand and gravel, but which one is better is the question.

Which is better sand or gravel for a fish tank? Gravel is a better choice for most freshwater aquariums. Many people choose gravel because it comes in many varieties of colors so that you can customize your tanks depending on your aesthetic.

Check out some of the topics I have prepared below which includes a guide that will help you to decide whether sand or gravel is better for your fish tank and why it matters in selecting the best substrate.

Gravel Substrate

Gravel is known to be the better choice for most freshwater fish tanks, and one of the major benefits of gravel is that it allows water to flow through it.

As a result, it can prevent the build-up of amoebas and bacteria in the substrate. If the amoebas have built up for too long, it can sicken your fish and lead to mold accumulation.

Gravel substrate is much heavier than sand, and it does not pull into the aquarium filters where it may tend to clog it or cause them to work less efficiently.

In addition to that, gravel comes in many colors, so you can customize your fish tank’s look and make it complement the fish you have.

Types Of Gravel

When it comes to aquarium gravel, there is no particular clear definition of it. Generally speaking, gravel ranges from 2mm to ¼ inch in diameter, which is actually the dried pea-size.

You can always buy gravel in bulk in your construction supply chains, but they are not usually safe for usage in many aquariums.

This type of gravel contains toxins and heavy metals that can easily poison your tank. You must always aim for products that are generally made for aquariums to get the best results.

Here are among the most common aquarium gravel you can choose and their benefits and drawbacks to one another:

1.    Live Gravel

They are pretty much similar to live sand, and these products come in pre-packed in freshwater and contain bacteria and microorganisms along with your substrate.

This type of gravel helps prevent the new tank syndrome ad it contains nutrients to help the plants grow and thrive. You do not need to rinse it before adding to your tank, and it is most compatible with freshwater species.

The only drawback for this type is that they are more expensive than the rest, and it only has a limited range of sizes and colors.

2.    Natural/River Gravel

As their name suggests, this type of grave is collected from the riversides and dug out of the gravel pits. They are processed and cleaned to a roughly uniform shape, and sizes and the tiny pebbles will appear smooth but usually not coated with a sealant.

Natural gravel comes with a variety of natural colors and texture, and it allows water flow through the substrate that can help to prevent dead zones.

It is also suitable for most freshwater animals, and they are chemically inert and will not alter the overall water quality. Natural gravel also permits all healthy bacteria build-up to become established throughout your substrate.

3.    Clay Gravel

Another great option for planted freshwater fish tanks is to use iron and some mineral-rich substrate made from clay.

This way, it can provide aquatic plants with a wide accumulation of nutrients in order for them to survive. It also allowed water to circulate through, and the healthy bacteria will be able to flourish.

Clay gravel is known to be chemically stable, and it will not alter or change the chemistry of the water. However, it is expensive compared to other options of gravel.

It is also worth mentioning that they are very dusty, and it requires a lot of rinsing before you add it to your tank.

Sand Substrate

Sand does not allow water flow through it compared to gravel. However, if you have a tank that includes fish that like to burrow and scavenge, this is perfect for you.

This is because your fish will be the one to filter the substrate. Many aquarium owners think that it is more natural-looking to have sand as their substrate.

It will look more natural, and it can mimic the lakes or riverbeds that makeup fish’s natural habitat.

In addition to that, a closely packed sand substrate needs less change compared to gravel.

This is because there are smaller gaps between the sand particles than the particles of the gravel. Most of the old food and plant matter will remain on top rather than sinking to the bottom, where they usually rot and decay.

Types Of Sand

When it comes to categorizing sand, you will only get it by the size of the particles. If a substrate is between 1/16 to 2 millimeters in diameter, it can be called sand regardless of what it is actually composed of.

This cannot be very clear to many people when you are searching for the appropriate substrate.

Sand can be utilized in so many ways and different industries, from construction to manufacturing.

Many sand products are actually not safe to use in a fish tank and are particularly unsuitable for freshwater tanks.

Here are some of the aquarium sand types you can choose and some notes on their benefits and drawbacks:

1.    Live Sand

Live sand can be described as living because they actually have natural aquatic bacteria in them and have other microorganisms. These bags come filled with either freshwater or saltwater, as well as the substrate.

This is a perfect choice because it can prevent the new tank syndrome. After all, bacteria can break down waste products and can maintain the chemical of the water.

Live sand does not need to be rinsed before adding to your fish tank, and they are typically more expensive than others.

It is also worth mentioning that they are not suitable for freshwater community tanks, but some products work well for some African cichlids and other aquatic species who like to have high water pH balance.

2.    Coral/Reef Sand

Coral reef sands are known to be made from crushed coral. These calcium carbonate-based minerals such as aragonite are the perfect substrate for you for many reasons.

When it comes to saltwater aquariums, reef sand is the most popular choice among others. On the other hand, these products are not suitable for freshwater fish tanks.

3.    Desert/River Sand

Desert River sand is most popular and marketed for terrariums, and these natural products are cleaned and processed uniformly in size and shapes.

It comes in a wide variety of natural shades to match your aesthetic decor. Most products are safe to use n most freshwater fish tanks as it will not change the water chemistry.

This type of sand is not actually designed for aquariums, and it can cloud the water or clog your filters even though you rinse it multiple times.

4.    Plant Sand

Plant sand is not actually sand, but it is a product that is usually made from iron-containing clay ground into small sand-sized particles. This gives plants with the nutrients they need to be able to survive.

It has porous clay particles that allow water to flow through, and it allows healthy bacterias to flourish. They do not change the water chemistry and are available in different numbers of colors.

5.    Pool Sand

Pool sand is actually used for filtration systems, and it is a pale-colored natural product that has been cleaned and sifted to a uniform size. Pool sand is economical.

You can purchase it in bigger quantities, and it is less likely to get clouded in aquarium water. It is chemically inert and will not change the water chemistry.

Which Substrate Should You Choose

This is the million-dollar question right here, but it is actually not hard to choose which one is better. It will always be according to your needs and what you actually need at the moment to be able to build your very own fish tank.

This is more than just an aesthetic choice, as it also impacts your aquarium’s set-up and longevity.

If you choose, gravel is a popular option for freshwater aquariums, but sand substrate may be a better choice for specific situations.


Figuring out which substrate to use can be challenging for people, both beginner, and experienced ones. This is because there is plenty of usage and benefits you can get from using gravel and sand.

To avoid any issues, you should pick the substrate that works best for your fish and plants you plan to keep in the fish tank of your dreams. Many fish will survive if you mimic their natural habitat, and everyone will be happy in the end.