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Types of Aquarium Substrate

Types of Aquarium Substrate
By Little Fields Farm 7 months ago 2401 Views

Many people do not realise the importance of choosing the right substrate for their aquarium until its cleaning time.

In case you are not sure, the substrate is the matter that is used to cover the bottom of a fish tank. Several types of substrate with varying textures, colours, and materials will be available at your local aquatic shop but selecting the one that you think will look best is not the ideal way to go about it.

Here’s what you need to know about different substrates in order to make the right choice.


Gravel is the most popular and the most commonly used type of substrate in most fish ponds and tanks because it comes in different sizes and colours. However, gravel that is meant to be used in an aquarium is modified slightly to be safe for use.

Its edges are smoothened so that the sharp sides do not harm the fish. Therefore, although gravel is readily available, if you intend to use it as a substrate then you must buy it from an aquatic centre exclusively.


Sand is the second most widely used substrate in fish tanks. It is available in various colours and this is what makes it ideal for use because you can select the hues that go best with the surroundings of your aquarium.

Sand must be used if you want to keep fish that like to bury or dig into ocean beds but you should avoid using it for tanks housing large fish or other aquatic creatures such as lobsters. This is because their movement is likely to cause a lot of disturbance to this medium. Also, remember that choosing fine sand can choke the filters and no matter what its grain size is, sand is always the most challenging of all substrates to clean.

Coral Sand

Coral sand is a special substrate that is made up of calcium carbonate. It gradually dissolves in water with the passage of time and therefore, needs to be replaced. The reason why many aquarium owners use this sand is that it balances the acidity in water caused by decaying organic matter and is also best for sustaining fish that live in high pH levels.

Marble chippings

This substrate also contains calcium carbonate but is often preferred over coral sand because it is cheaper and unlike coral sand, it is available in several shades. However, it goes without saying that marble chippings are heavier and less porous than sand.


Although solid marbles are usually used as a decoration over other substrates discussed above, sometimes they can are also used on their own.

Spreading flat marbles of different hues on the bottom of your aquarium will give it a really chic look. But marbles are not recommended for use as a substrate because the gaps between individual pieces are quite large. This not only means that large chunks of food and waste can accumulate in the empty spaces, but it also leads to building up of bacteria that can harm or damage the delicate ecosystem in your fish tank.

Now that you know more about substrates, think wisely before you make a decision on which one to get for your tank. Choose the one that meets your requirements and one that also provides a unique visual flair.