How Much Gravel Do You Need For Your Aquarium?

Every fish owner will always ask questions including how much gravel or any substrate they should put in their fish tank. Gravel is an aquarium accessory that is essential because it helps the overall well-being of your aquarium.

Whether you are a total beginner or an experienced aquarium owner, you should know how to calculate the substrate amount in your aquarium.

How much gravel do you need for your aquarium? In a general sense, you should add about 1 pound of substrate per gallon of water. This means that if you have a 5-gallon fish tank, you should at least put 5 pounds of gravel in it.

In this article, you will find useful tips on how much gravel you should put in your aquarium. This is important to know so you have the proper ratio of the water level, gravel weight, and its plants.

What Is Gravel?

There are multiple substrates available in the market today that are basically used as based on most aquariums or fish tanks. One of the most popular and common substrates used as a base later is gravel.

Gravel is mostly made from rock fragments and ranging from granules to boulder-sized pieces. It has larger pieces as compared to other substrate types, and it is very porous.

Since the graver’s weight is mostly heavy, they remain intact for longer and can be flexible too.

When it comes to depth, it is usually between 1 and 3 inches, and when you are trying to figure out the quantity of the gravel, you should always consider the needs of your fish, hygiene maintenance, and the allowable minimum depth.

Using Gravel For A Fish-Only Aquarium

As you all know, gravel is used mainly in a fish-only tank because it provides a beneficial bacteria bottom for the aquarium. The fundamental purpose of the gravel is to allow bacteria to grow and build colonies within it.

It is important to establish and maintain a balance of healthy bacteria in your aquarium to help your fish thrive in the water. It can also serve as an orientation to your fish.

If you do not have a base layer such as gravel that is present in your tank, the galls and reflections will cause the fish to become disoriented.

This is because of the extreme amounts of stress, and as a result, it can lead to their death. If you opt for a gravel base layer in your aquarium, then a depth of 1-2 inches of gravel will be adequate.

If you have haver bottom dwellers in your tank, you should add more depth to the gravel while making sure that the substrate is finer compared to a coarse one. Even for some basic usage, the consistency and texture of the gravel have a huge impact.

Factors To Consider When Using Gravel

When looking out for the type and quantity of gravel needed in your aquarium, there are some factors and things to consider before you get one for yourself. Here are some factors that you should consider when using gravel in your aquarium:

Type Of Fish

This is the most important thing to consider because it will determine the type of gravel you need and its quantity. Some fish prefer coarse gravel because they want to mess around it. Others prefer finer gravel in which they can dig and forage.


Another main factor that will determine the quality and quantity of the gravel is the plants you will have in your aquarium.

When it comes to plants, there are some without root systems, and they are least bothered by the type of gravel in the aquarium.

However, some rooted plants can get affected by the kind of gravel you use for your fish tank base.

Big rooted plants need to have a deep layer of fine gravel, while on the other hand, small plants tend to have smaller root systems. Therefore, it can easily survive with a shallow layer of coarse gravel.

Size And Decoration

The size, dimension, and total number of gallons it can accommodate will determine gravel requirements for your aquarium.

The bigger your aquarium is, the more gravel it needs to be able to get the minimum depth of it.

Amount Of Gravel Needed

If you take all the considerations mentioned above, then finding out the gravel quantity will be very smooth. For starters, 2 inches of gravel is enough.

It is a great base for a freshwater aquarium. 2 inches is actually the minimum amount of gravel required as a substrate so that it will be enough for your aquarium.

As mentioned above, another important factor to consider is the dimension and the size of your fish tank.

The aquarium’s size needs to be exact, and it is a no-brainer that the bigger the size of the tank, the more gravel you need to form the base layer.

To calculate the amount of gravel you require, you must multiply the aquarium’s depth in inches by the amount of gravel you have calculated per inch.

In a general sense, you should add about 1 pound of substrate per gallon of water. This means that if you have a 5-gallon fish tank, you should at least put 5 pounds of gravel in it.


As a conclusion, it is very important to pay close attention to all the factors mentioned above in this article. The reason is that all these factors will affect how much gravel you need for your aquarium. The size, dimension, and depth of the fish tank matters.

Aside from that, it is worth mentioning what type of fish you plan to put inside the tank. Another important matter of adding gravel to a fish tank is its proper maintenance.

Although you don’t have to replace the gravel in your aquarium pretty much often, vacuuming your high-quality gravel particles should be enough.