Believe it or not, the first thing you add to your brand-new aquarium isn’t water.

That honor goes to the substrate.


I’ll answer that and more in my beginner’s guide to aquarium substrate!

What is a substrate?

You actually already know what a substrate is. You just don’t call it by that name…

When it comes to aquariums, the substrate refers to any loose material that makes up the bottom of your tank.

You know those pebbles at the bottom of your aquarium?

Well, that’s the substrate.

Pretty simple, huh?

It doesn’t have to be pebbles. It can be anything. If it’s loose and covers the bottom of your aquarium, it’s a substrate.

Why do aquariums have a substrate?

Below are the most common reasons why a substrate is used in aquariums…

1. Good looking – Let’s be realistic. The main reason people use a substrate is because it enhances the look of the aquarium.

2. It’s natural – Do fish in the wild have a glass-bottomed habitat? No. By using a substrate, you are creating a more natural environment for your fish.

3. Enhances your fish – You can use the substrate to make your fish pop. Dark fish are easier to see on a light-colored substrate while light-colored fish are easier to see on a dark substrate.

4. It houses bacteria – You know those beneficial bacteria that take part in the Nitrogen Cycle? While the majority of them live in your filter, some also cover the substrate of your aquarium. In fact, you can use the substrate from an established tank to make your brand-new aquarium cycle faster.

5. Plants need it – Plant roots need to go somewhere. Without a substrate, your plants will float to the top of your tank.

As you see, there are some pretty compelling reasons to use a substrate in your aquarium.