Black Aquarium Sand or White Aquarium Sand?

Black Aquarium Sand or White Aquarium Sand?7 mins read

Fact checked by
Sydney Perry
Reading Time: 9 minutes
Black Aquarium Sand or White Aquarium Sand
Image from Flickr

Aquarium sand is a gentle and soft substrate that can be beneficial to use in place of gravel or less common alternatives such as scaper soil. In many instances, fishkeepers prefer aquarium sand because of its more naturalistic, mature look. Furthermore, sand can be gentler on the delicate stomachs of pleco fish and other bottom dwellers such as cory catfish.

This article will go into the different types of aquarium sand and when and why to use them, because they are not all the same. Furthermore, different colors tend to mean the sand comes from a particular kind of rock, which may raise or lower the pH of your tank accordingly.

Why Use Aquarium Sand?

Why Use Aquarium Sand?
These species of fish are bottom feeders, and they have evolved to move along the bottom of a lake or river. Image from Flickr

Aquarium sand is not just popular for its natural look, it can often be the only choice if you want to keep certain kinds of fish. In fact, many popular bottom-dwelling fish like Cory Catfish, Oto Catfish, Pleco Fish, and more, all require freshwater aquarium sand in order to properly thrive. They can work well with both black or white aquarium sand.

Why is this?

These species of fish are bottom feeders, and they have evolved to move along the bottom of a lake or river. As they do this, they hoover up detritus that falls from the surface. As a result, they often have flattened bodies and soft stomachs. These allow them to move easily while hugging the bottom. However, a side effect of this means the skin on their stomach is very delicate. Due to this, it can easily become damaged by gravel.

These fish are very popular! Therefore if you are even thinking of keeping any bottom-feeding algivores in your tank, you will have to consider aquarium sand. Luckily, there are lots of colors of freshwater aquarium sand to choose from. In fact, they even affect the quality of the water. Read on to find out more.

Difficulty Choosing Between Black Or White Aquarium Sand

At a most basic level, choosing white or black aquarium sand is an aesthetic preference. Although when you purchase different colors of freshwater aquarium sand you are also purchasing different types of rock, unless your sand contains dye. There’s a bit of chemistry involved here, which we’ll go into later. However, for now, let’s assume that you’re buying freshwater aquarium sand made from a basic rock that is pH neutral and has simply been dyed to the color of your choice.

It’s common that you can find this in any good aquatic store, so just ask.

Again, ultimately this is about aesthetics. So, a few things you may want to consider include:

  • The color of your fish. Do you want to easily be able to find them against a backdrop of a different color? This is especially so if you have bottom dwellers.
  • The color of your plants (some stand out better with white or black aquarium sand, for example)
  • The rest of your tank setup
  • Your simple preference

What Alternatives Are There To Aquarium Sand?

If you don’t like aquarium sand or have decided these two most common colors are not for you, there are some other options you can go for. We’ve also included here some options that are technically not sand but which you may find with sand at the aquatics store.

What Fish Work Best With Aquarium Sand?

What Fish Work Best With Aquarium Sand?
Aquarium sand is a vital component of the tank for many varieties of fish that dwell on the bottom. Image from Flickr

Overall, freshwater aquarium sand is a vital component of the tank for many varieties of fish that dwell on the bottom. As we mentioned above, this is because these fish have delicate stomachs and they don’t like to move around on gravel as it hurts them. These kinds of bottom-dwelling fish include:

  • Dojo loaches
  • Kuhli loaches
  • Oto catfish
  • Cory catfish
  • Many pleco species
  • Chinese algae eater
  • Siamese algae eater

Black Aquarium Sand Or White Aquarium Sand?

Beyond a simple matter of preference, some aquarium substrates have different chemical properties. In fact, the different colors generally indicate that these kinds of sand come from different types of rock.

In any decent aquatics center, these generally have labels, so you will know whether you are buying simple pH-neutral sand that has a colored dye, or freshwater aquarium sand from a certain rock variety. Generally, black aquarium sand will have a dye added to it more frequently than white aquarium sand, which also includes neutral or cream colors.

If you are going for raw sand from different rock types, they normally have minerals in them. As a result, they can have effects on the pH of your tank, and different ones are suitable for different fish. So, read on for the low down.

Differences Between Different Sand Colors

The most basic difference between different sand colors is that they are made of different substances. Black-colored sand tends to be made of igneous (volcanic) rock, whereas white aquarium sand often comes from crushed coral. However, cheap sand may be made from a basic rock like granite which has then been dyed a certain color. Always check the back of the package!

Dyed freshwater aquarium sand is not usually a problem for your fish, but you can definitely create a more naturalistic environment if you go with the real thing. This may also have a mineral composition in the water that is more true to your fish’s natural habitat, too.

Sand Colors And pH

By far the biggest tank parameter that sand can affect is pH. As we mention above, black aquarium sand often comes from igneous or volcanic rocks. On the other hand, white aquarium sand usually comes from crushed coral.

These both have a noticeable difference in pH. Crushed coral is slightly alkaline, meaning that it will raise the pH of your tank. Meanwhile, volcanic soil or lava soil – which is often mistaken for black aquarium sand – will lower the pH of your tank. Sometimes this can be quite considerable, which is useful if you have fish that are from a naturally acidic environment, such as angelfish. However, plain old black sand, if made from an igneous rock, can also have this pH-lowering effect, albeit at a lower level.

Composition Of Different Sand Types

You may occasionally find another type of rock in aquarium sand, but this guide will mostly cover lava soils, which are black (or occasionally red), and crushed coral, which is white. You may see both of these in the same section as the aquarium sand.

  • Composition Of Black Sand

Black aquarium sand is generally either neutral sand that the manufacturers added a black dye to,  or made from lava rock. If it is made from lava rock, it will generally say so on the packet. This type of sand generally comes from basalt and other igneous (volcanic) rocks. As a result, the pH depends on where it came from.

There can be trace elements of sulfur in volcanic rocks, which can lower the pH of your tank. However, it should say on the packet whether this is the case for any given lava sand.

If your lava sand is pH neutral, it can actually help buffer pH. This means it prevents large pH fluctuations in your tank. It also has a beneficial effect on plants, because it can promote the growth of symbiotic bacteria. These are bacteria that help your plants grow due to the waste they produce.

  • Composition Of White Sand

As with black aquarium sand, you can have white sand that is simply dyed. However, some of your white aquarium sand may come from coral. You will see it listed in the aquarium shop as ‘coral sand’. Similarly to black volcanic sand, it will also be either ‘soft grain’ or ‘coarse grain’. If you are keeping bottom-dwelling fish, it’s best to get a ‘soft grain’ coral sand. This is easier on the stomachs of your algae eaters.

Best Fish For Black Sand, Lava Soil, and Scaper Soil

Best Fish For Black Sand, Lava Soil, and Scaper Soil
For pH-neutral scraper soil (which also looks black), neutral lava soil, or neutral black sand, you will find most popular freshwater fish are suitable. Image from Flickr

For pH-neutral scaper soil (which also looks black), neutral lava soil, or neutral black aquarium sand, you will find most popular freshwater fish are suitable. However, if you have lava soil that is slightly acidic, this is a great chance to make a habitat for blackwater fish like angelfish and other Amazonian fish.

Some good examples include:

  • Angelfish
  • Some pleco species
  • Discus fish
  • German rams
  • Amazonian tetras

Best Fish For Crushed Coral and White Sand

As mentioned, neutral freshwater aquarium sand is great for all kinds of fish. But the high pH that white crushed coral sand creates is perfect for cichlids from the African Great Lakes regions.

These fish often have very specific needs in terms of a high pH. It’s best to thoroughly research all these species before you buy them, as not all of them are suitable for beginners. Remember also that white aquarium sand does not necessarily indicate it is made from coral.

Pros And Cons Of Using Different Types Of Sand

As we’ve broken down, the kind of sand or substrate you use affects the pH of the tank a lot. Therefore, you can actually modify and balance this with the freshwater aquarium sand that you choose. This can be both a pro and a con and comes in hand with other challenges depending on what fish you have.

pH Fluctuations

pH fluctuations can happen in any tank, however, they are generally a sign that some things are not right with your nitrates cycle.

Test the pH of your tank with a store-built test if you suddenly see your fish acting strangely. Another telltale sign is dying plants.

Fluctuations can happen if your filter stops working properly, leaving to nitrate build-up, or if you need to change the filter. Sometimes, there could be a change in the quality of the water where you live. So, if you are using tap water to top up your aquarium when you clean it, this can be why.

Mineral Concentrations And Different Fish Types

Some fish need very specific water parameters. We cover some of the main ones below, however, it’s always best to research each individual species.

  • Malawi Cichlids

Malawi cichlids need a high pH! These fish live in highly alkaline environments with lots of minerals. Therefore, crushed coral, or white aquarium sand that is made from coral, is an excellent choice for your tank. It can also help buffer the pH in general.

White sand is also great aesthetically for this kind of cichlid tank. Malawi cichlids often live in habitats that have rocky walls and crevasses but not much vegetation, instead, the lakebeds they are used to in the wild have large expanses of sand. Therefore if you want to mimic this setup, crushed coral is a great choice.

  • Blackwater Fish

Blackwater fish, on the other hand, live in highly acidic environments, with pHs that reach sometimes as low as 4.5 or 5.5. These kinds of fish include Angelfish, discus fish, and many Amazonian cichlids.

Therefore, soil made from igneous rock or even specialist lava soil (although not the same as black aquarium sand) can be very useful for these fish in maintaining the ideal pH that they enjoy. Freshwater aquarium sand does not necessarily provide this so if you wish to use it, add it on top of your lava soil layer.

You can also lower the pH by adding driftwood, which adds tannins to the water. These fish all love a tank with lots of vegetation, and sometimes even floating plants on the surface.

Common Problems and Troubleshooting

Common Problems and Troubleshooting
If you had previously had gravel in your tank, you might find that pleco fish and other bottom dwellers can injure their delicate stomachs on it. Image from Flickr

No matter how well you set up your tank, you may occasionally run into some problems. These can be connected to your water parameters, so may have a link to the substrate you use. Either way, here is some quick info:

1. Plants Dying

If your plants are dying, it can be for a few reasons apart from the type of substrate you used. These can include pollution in the tank, vitamin deficiencies, and lack of sunlight, as well as being eaten by your fish. Sometimes, the substrate you use can cause digging behavior. In fact, sand can enable goldfish to dig plants up more easily.

However, if you have freshwater aquarium sand alone, this can often be a reason why plants fail to thrive. Without a soil-based substrate to take root in, they simply won’t be able to get the necessary nutrients they need. This is why it’s always good to start with a soil-based substrate and then add the sand of your choice over the top of this.

2. Pleco Fish Stomach Injuries

If you had previously had gravel in your tank, you might find that pleco fish and other bottom dwellers can injure their delicate stomachs on it.

To prevent the wound from getting infected, you can put your fish in a saltwater bath to kill any bacteria. Keep the fish there until it looks like the injury has healed. Then, you can return the fish to the main tank. You may also wonder how to clean aquarium sand to prevent infection. If you have an aquarium vacuum, remember this is a great way to clean sand from detritus. However, good tank hygiene overall prevents freshwater sand from harbouring harmful bacteria.

3. pH Changes Due To Sand

If you’ve added sand and now found you have had problems in your tank, this may be due to the pH changes that come from different types of rock.

Check the packet! You can always remove and replace it, and leave time for your water to go back to normal.

Final Thoughts

There are lots of substrates you can buy for aquariums, but they are not all interchangeable. Some fish have very special requirements in terms of substrates, so it’s best to do your research. Whether you choose black or white aquarium sand, good tank hygiene and a thought out setup is always best for any fish.

However, if you want to create a true-to-nature environment for your fish, you may opt for sand, especially for species like Malawi cichlids. Therefore, it’s best to know your way around aquarium sand, and hopefully, this guide should help you get started.

Frequently Asked Questions

Are black and white aquarium sand the same?
Generally, if you are buying dyed sand, different colors should be pH neutral and essentially the same. However, if you are buying lava soil or crushed coral, both of which can look like sand, they are not the same and can influence the pH of your tank.
Do pleco fish need aquarium sand?
Yes, pleco fish generally should ALWAYS have aquarium sand. These fish have very delicate stomachs. They also move along the bottom of the tank, wriggling their stomach on the substrate, while they eat. Therefore, they will need a substrate that is soft enough that they don’t get hurt.
Is lava soil the same as black sand?
You can think of it this way - you can generally classify all lava soil as black sand, based on how it looks. But not all black sand is lava soil or even made from volcanic rock. Sometimes it is just made from regular rock that has a black dye. Therefore, if you’re looking for the unique properties of volcanic rock in your aquarium, ensure you buy specialist laval soil for this purpose.
View sources

Tal Halperin

Tal is an avid fish keeper and has been raising ornamental fish for decades. As a little boy, he drove his father crazy to buy him an aquarium with all the necessary equipment. Now, after a career in the field, he has set up Your Aquarium Place to offer the most comprehensive guide to ornamental fish keeping available and share his passion for the different species he has looked after.