Do you need to have rocks in your fish tank?

Rocks are not a requirement for a fish tank, but they can provide several benefits. Rocks can help to create hiding places for fish, provide a natural substrate for plants to grow on, and help to maintain the water quality by absorbing toxins. Additionally, rocks can add a decorative element to the tank and make it more visually appealing. However, it is important to choose rocks that are safe for fish and do not contain harmful substances.