Choosing Sand & Gravel Substrate

Charutha Bandara is an Indianapolis software engineer who guides Aegis Studio, a software development company. Outside of work, Charutha Bandara is passionate about marine life and sells aquarium supplies on his website Ceylon Aquatics.

When creating and maintaining an aquarium, one basic decision point for freshwater aquariums is the substrate used. This often boils down to sand versus gravel. An advantage of the latter is that it lets water flow through easily, which prevents bacteria and other grime from building up and causing harmful aquarium mold. At the same time, the heaviness of the gravel ensures that it doesn’t get pulled into filters and start to clog them.

While sand doesn’t provide easy water flow-through, this task can be accomplished by fish that feed by burrowing and scavenging. It is also more natural, in that it mimics outdoor habitats such as riverbeds and lakes. Finally, the tightly packed quality of sand means that plant matter and uneaten food particles are more likely to remain on the top of the substrate. This is in contrast to gravel, which needs to be changed more frequently, as food tends to fall through the gaps and decay at the tank bottom.