Aquarium Sand vs Gravel: Pros and Cons

Last Updated on 2023-08-08

If you’re not sure whether you should use aquarium sand or aquarium gravel, then you’ve found the right article! In this article, not only will you find out which substrate is better for your aquarium, but you’ll also learn why and what’s going to be best for you as well!

So keep reading to find out everything you need to know!

Aquarium Sand Summary

Aquarium sand is a great substrate option if you want your tank to look like a serene river or lakebed. The bottom of a freshwater aquarium can be made of sand, which is both an affordable and visually pleasing choice. It can be as fine as flour or as coarse as gravel, and sand comes in a wide range of colors, sizes, and textures. The grains of sand found in nature range in size from about 1/16 inch to about 2 millimeters and can be composed of organic material, shells, and rocks.

Sand for aquariums can be generated artificially from a silica basis, or it can be made from crushed quartz, coral, or minerals like aragonite. Aquarium sand, in contrast to real sand, is perfectly rounded and free of any sharp edges that could harm fish and other aquatic life. Products sold in stores may be described as “river sand” or “natural sand,” and they might resemble the sand found at the beach or a riverbank. The bags of substrate, in contrast to sand taken fresh from a river, have already been treated and cleaned.

Types Of Aquarium Sand

Selecting the appropriate sand is crucial when setting up a new freshwater aquarium or upgrading an existing one. Listed below are the most popular options for aquarium sand:

●      River Sand

The sand from the river is an easy and inexpensive substrate option. With one exception, it must be completely devoid of clay. Oxygen is vital to the survival of aquatic life in an aquarium, and the larger grains of river sand help bring that oxygen to every part of the sand bed. River sand has the drawback of releasing color for extended periods of time. Furthermore, it can be sharp in some instances.

●      Black Quartz Sand

Sand grains are different colors because of the minerals—ilmenite, magnetite, or hematite—that are mixed in. Black quartz sand is safe to use in the aquarium because it does not affect the pH or hardness of the water. There is no need to worry about an increase in water hardness.

●      Pool Filter Sand

Even though it wasn’t intended for this purpose, some people use it in aquariums. With its relatively large grains, this sand is less likely to be affected by hydrogen sulfide gas, which is a plus. Because of its weight, pool filter sand cannot be sucked up by the filter. Choose stem plants that can get their nutrition from the water when using pool filter sand in a planted tank. Otherwise, you may need to insert root tabs if you have plants that rely on their roots for nutrition.

●      Play Sand

A different variety of sand used in aquariums. The original purpose of this sand had nothing to do with fish tanks. As opposed to pool Filter sand, it is much lighter and smaller in size. Take extra safety measures with Play sand. Make sure it doesn’t contain any CaCO3, as that would be bad for freshwater aquariums.

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Benefits Of Aquarium Sand

  • The use of sand as an aquarium substrate is always a viable alternative. It’s aesthetically pleasing, and it gives off a natural look.
  • Sand substrate is widely accessible at low cost from a variety of local fish, aquarium, and pet stores.
  • Some plants thrive with their roots buried in sand, so that’s another major perk of using it as a substrate. It can serve as a solid foundation, and some varieties are even fortified with nutrients that can be used by the plants.
  • When it comes to waste management, sand may make cleaning your fish tank a breeze.
  • Sand also has the added benefit of being a good place for fish, snails, and other creatures to make burrows.

Downside Of Aquarium Sand

  • The majority of sands are too dense to support robust root development, and most aren’t fortified with the nutrients that plants require.
  • Sand is also notoriously difficult to clean up (and it needs time to settle properly). Sand can cause problems in a number of ways: it can get sucked into filters, it can block tubes, and fish can stir it around.
  • The formation of anaerobic dead zones is a major downside of sand substrate. These are pockets of gas that can hurt or kill fish and plants if they are disturbed. This is a common problem in areas where the sand is not continuously stirred and moved.

Aquarium Gravel Summary

Gravel is by far the most common variety of aquarium substrate, and it is an excellent choice for the majority of freshwater aquariums. If you go with a gravel bottom, you’ll have a wide range of options available to you in terms of size, color, and composition of the gravel. Gravel is often crafted from rocks like quartz or sandstone that have been broken down, smoothed down, and molded into the desired shape by the use of various crushing and grinding techniques.

Gravel often ranges in size from just above 2 millimeters to a quarter of an inch in diameter, which is roughly equivalent to the size of a dried pea.Gravel might have a consistency that is almost identical to that of sand, or it can look like a pile of stones at the bottom of your tank. It is possible to treat artificial aquarium gravel with a vividly colored paint or dye and then seal it so that the color does not flake off.

Types Of Aquarium Gravel

Aquarium gravel, also known as substrate, is available in many different hues and sizes, from fine sand and pebbles to massive river rocks, all of which contribute to an aquarium’s aesthetic appeal. While there are times when a substrate isn’t needed, it serves various other reasons that are just as significant.

Take a look at the following list of the most popular aquarium gravel types and its characteristics.           

Live Gravel

Like live sand, these goods arrive with bacteria and microbes already present on the substrate. Aside from perhaps containing nutrients that assist planted tanks to thrive, it helps avoid new tank syndrome. It doesn’t even need to be rinsed before being added to your freshwater aquarium! It’s more expensive than competing products and comes in a smaller variety of sizes and colors.

Natural or River Gravel

These materials are gathered from riverbanks and gravel pits, as their names suggest. They’re sorted, cleaned, and processed so that they’re all the same size and shape. While the tiny stones might look sealed, they typically aren’t. It offers a rich palette of natural tones and textures. This substrate is suitable for most freshwater creatures since it allows water to flow through it and eliminates dead zones. It has no effect on the chemistry of water and hence does not pollute it.

Gravel Made with Clay

Soil rich in iron and minerals can be found in clay, which is another choice for freshwater aquariums with plants. A healthy dose of nutrients found in clay gravel is just what aquatic plants need to flourish. By allowing water to flow through it, dead zones can be avoided, and beneficial microorganisms can thrive in the substrate.

Many types of freshwater life can thrive in this environment. As far as water chemistry goes, clay is a good choice because it is chemically inert and non-toxic, but it is also more expensive than many other options.

Artificial Gravel

The majority of these items are created using silica or industrial resin. You may also find them with an acrylic coating that mimics the look of genuine gravel. Glow-in-the-dark and black-light-reactive varieties are available, along with a wide range of other colors and sizes. As long as you give it a quick rinse before putting it in the tank, it should be fine for most freshwater creatures.

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Benefits Of Aquarium Gravel

  • You can find gravel substrate at almost any store that sells aquatic supplies for a low price. It’s not hard to find at all.
  • In almost all cases, gravel is preferable to sand when it comes to plant growth. The rocks and the small gaps between them make excellent rooting substrates, and plants are thus able to rapidly expand their root systems.
  • Another fact about most gravel that you might not know is that it is inert. This means that the water chemistry in your tank won’t be affected by the gravel substrate you choose.
  • Gravel is usually too big and too heavy for fish, air pumps, water pumps, or filters to stir up. Since it is too heavy to float, it does not clog aquarium parts or produce cloudy water like sand does.

Downsides Of Aquarium Gravel

  • Unconsumed food, fish waste, and other organic matter can easily slip through the cracks between the rocks when using a gravel substrate. This can make it more difficult to keep your aquarium clean, as organic debris will become lodged between the rocks and require the use of a gravel vacuum to remove. It can cause water quality problems, at the very least.
  • Some fish have been known to try picking at gravel. It’s bad for their health in general and bad for their teeth, digestion, and buoyancy.
  • Gravel is not the best choice for aquariums with fish that prefer to burrow in the substrate, as the sharp edges of the gravel can cause serious injuries to the fish.
  • Also, gravel may harbor bacteria that, if ingested by a scratched fish, could lead to an infection and even death.

What To Consider When Choosing

Even though sand and gravel appear to be very similar, they each have their own set of advantages and disadvantages. There are a number of factors to think about when deciding which one to use, including the fish species you plan to keep in the tank. Check out our handy guide to learn which option is best for your fish tank.

The following are some of the most important factors to think about before choosing between sand and gravel.

Impact on Your Fish

You should probably go with sand instead of gravel if you have fish and other animals that like to mess with and burrow in the substrate. Think about how the substrate you pick will affect your fish. You should learn more about the environment and habits of your fish. Then you can strike a chord between your aesthetic preferences and those of your fish.

Planted Tanks

As an alternative to sand, gravel is the best option for a planted tank, or one that contains a lot of aquarium plants. Both the nutrients and the root structure will benefit more from this.

Filtration and Cleaning

This has benefits and drawbacks, so to speak. Sand is preferable because trash doesn’t get buried and is difficult to remove, as it does with other materials. Nonetheless, sand is easily dislodged, creates a mess, and is sucked into filters. In addition, unlike sand, gravel can be washed alone in the kitchen sink.

Both the fish’s well-being and the cleanliness of the tank are greatly affected by the particle size of the substrate you use.

Replacement of the Substrate

The sand will need to be replaced periodically, which can be quite an ordeal. In most cases, gravel only requires a good washing rather than a complete replacement.

Chemistry of Water

In terms of the chemistry of the water, either sand or gravel will do as long as it is an inert material. Just watch out for sand and gravel that could potentially raise the levels of nitrate, ammonia, or pH in the water.

How Much Gravel Or Sand Should You Use?

It is recommended that the depth of your substrate be between 1.5 and 2 inches. Strong, long-rooted plants require deeper substrate, so this is something to think about.

Reduced sand depth will help prevent the formation of anaerobic patches, which can be a serious problem. Typically, a sand substrate should be about 1–1.5 inches deep.

There are some things to keep in mind.

1. There won’t be as much room for ornamental fish, plants, and decorations if the substrate is too thick.

2. Sooner or later, you’ll have to clean your substrate. And the more there is, the more you’ll have to clean up. Additionally, when viewed from the side, thick substrates appear unnatural.

A perfectly flat surface is not required for the substrate. Instead, you can build up the substrate in certain areas of your tank. Create a one-of-a-kind focal point for your aquarium by sculpting the surface into hills, mounds, and slopes. This is especially typical in the aquascaping community. It’s like landscaping but for an aquarium.


Can You Use Beach Sand in An Aquarium?

Beach sand is not suitable for any aquarium, especially freshwater tanks. Seawater, with its extreme chemistry and abundance of toxic compounds, has contaminated the beach sand. Although it might seem reasonable to use beach sand as a substrate for aquatic animals, doing so is actually quite harmful.

Can You Mix Sand and Gravel in A Fish Tank?

Aquariums can use both sand and gravel, but the gravel will end up on top as the sand settles to the bottom if you put it in first. When employing under-gravel filtration, sand cannot be used because the motor will not be able to draw water through the gravel and the compacted sand.

How Often Should You Clean Aquarium Gravel?

The rate of waste buildup in the fish tank gravel will determine how often it needs to be cleaned. Tank size, number and type of fish, presence of live plants, filter strength, and other factors all play a role. If the chemistry of the water becomes unbalanced, the gravel should be cleaned.

Can You Put Too Much Gravel in A Fish Tank?

Too much gravel will take up valuable room and stress out your fish. Additionally, since less water is available, harmful chemicals will accumulate more rapidly the thicker the substrate.


One of the best parts of maintaining a freshwater tank is the flexibility it offers. In addition to the physical parameters of your tank, you have complete control over the contents, from the fish and decorations to the substrate used to cover the floor of the tank. If you want to provide the best environment for your fish, you’ll want to do some research to choose a substrate that meets their demands and also suits your aesthetic preferences. Using this article as a guide, you can make a long-lasting and satisfying decision for your aquarium’s substrate after giving some thought to the key factors to consider.

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