The Ultimate Fish Tank Question: Sand or Gravel

Photo by: Bigstockphoto
Photo by: Bigstockphoto

Sand and gravel are two of the most common aquarium substrate. And because both aquarium substrates are popular, many aquarium owners are torn between the two. So which is the better substrate? Let’s get down to the nitty-gritty details:

Using Sand as Aquarium Substrate

Because most tropical fishes originate from sandy environment, using sand as an aquarium substrate is the best material to replicate the natural habitat of fishes from freshwater lakes or oceans.

Sand, as aquarium substrate, is perfect for fishes that exhibit burrowing behavior like gobies or fish that exhibit sifting in the mouth. Sand is also the better choice if you have bottom-feeding fishes.

However, because sand packs tighter than gravel, using it will form dead pockets of space within the aquarium floor. Dead pockets of space can lead to having little to no water circulation — and this is harmful for both fishes and plants. This can be prevented by not layering the sand too thickly. You can also stir the sandy floor regularly or even introduce certain critters, like snails, to circulate the sand for you.

Avoid using sand if your aquarium is fitted with an under-gravel filtration system because sand particles could block the tubes during siphoning. In addition, don’t use sand as aquarium substrate if your aquarium is made from an acrylic material because the finer particles will scratch the surface.

Using Gravelas Aquarium Substrate

Between the two popular aquarium substrates, gravel is the most commonly used because it’s easily available and more affordable. Gravel also comes in more colors — perfect for pet owners who value the aesthetics of their aquarium. Aquariums with gravel substrate are also much easier to maintain because it’s easier to handle than sand.

Just like sand, the particle sizes could pose an issue for some aquarium owners. Because gravel comes in various particle sizes, you can also customize your design accordingly. Gravel with particles that are too large can cause build-up between gaps thateventually affects the biology of the tank. In addition, gravel with large particles could also scratch or irritate the skin of fishes with delicate skin.

Gravel as substrate is best used for aquariums with live plants because it provides safe anchorage for their roots.

Ultimately, the best choice will depend on two things: aesthetics and the type of fish and plants you plan to keep. For example, if your aquarium is full of tropical fish species, then sand is the best substrate for your setup. On the other hand, if you value aesthetics and easy maintenance over anything else, then gravel is the best choice.

The setup of your aquarium will also be a factor in deciding which substrate is best for your needs. If your filtration system is easily clogged during siphoning, you might want to switch to gravel because the larger particles won’t be sucked into the filtration system.

We recommend going to your local pet store and asking the experts before choosing between sand and gravel as aquarium substrate.