Substrate

Substrate is not actually an essential part of an aquariumn. Bare-bottomed tanks are absolutely a 'thing', but having a substrate brings about more pros than cons.

1. Good looking
2. Natural - By having a substrate, you are creating a more natural environment for your fish
3. Enhances your fish visually - You can use substrate to make your fish pop, especially if the substrate colour and your fishes' colour contrasts
4. 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.