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How Much Sand Should You Have In A 55 Gallon Tank?

Giving fish the best possible environment to live in is a priority for all pet fish owners. That’s why it’s essential to know how much sand will be enough to make them happy.

You should have between 25 and 145 pounds (11.3 and 65.8 kilograms) of sand in a 55 gallon tank, depending on its shape and the type of fish you want to keep. Your desired depth will also influence the amount of sand; a shallow layer will need less sand.

This article will help you calculate how much sand you’ll need for a 55 gallon tank. We’ll also talk about different types of sand and all the equipment you need for this type of tank.

Why Sand Makes a Great Substrate

how much sand for 55 gallon tank
Although many fish lovers feel that gravel is better for fish tanks, sand is often a favorite choice.
This is because sand feels more natural and is better at mimicking the riverbeds and lake environments that fish thrive in. It also doesn’t allow water to flow through it as easily as gravel does.

Closely packed sand substrate won’t need replacement as often as gravel, which can be a great bonus for busy fish owners.

Old plant matter and food also tend to stay on the top rather than sink and decay.

Certain fish and plants also just prefer sand over gravel. Some species of cichlids, for example, consume sand particles as it helps them to digest their food.

On the other hand, goldfish can suffer intestinal blockages if they accidentally ingest sand. So, the choice really depends on the fish you have and what fish you plan to add to your tank in the future.

The Functions of Sand in a Tank

There are several functions that sand fulfills when used in a fish tank. Let’s take a closer look at them so you can be sure you want and need sand in your tank.

Biological Filtration

If you have a saltwater fish tank, you need biological filtration, which bacteria that grow on the rock and sand in your tank does. Sand gives the bacteria plenty of space to grow and thrive.

Your tank must have biological filtration to break down the toxic ammonia fish produce as waste products. Although there are other options such as chemical filtration, biological is the most natural and cheapest solution for your fish tank.

Aesthetic Appeal

One of the main reasons people first think about using sand is that it looks nice and natural. If you want to fill your tank with colorful fish and do some aquascaping, you’ll love sand.

You can create a beautiful tank that is healthy and attractive if you use sand intelligently.

Burrowing or Sand-Sifting Creatures

Many ocean creatures such as snails, worms, jawfish, and shrimp need to live in areas with a sand substrate. They all play a role in keeping your tank healthy and clean. These creatures eat algae and debris in your tank without negatively affecting your fish.

Potential Denitrification

Denitrification is a necessary process that removes nitrogen from the tank. It is essential that you have a sand bed deeper than 6 inches (15.24 cm). At that depth, oxygen can’t reach the bottom sand layer.

A fish tank with a deep sand bed is good at turning ammonia into nitrites and denitrification.

Live Sand or Inert Sand in Your Fish Tank?

You can use either inert sand (also known as dry sand) or live sand in your fish tank. Live sand gets its name because it has been cultured with bacteria.

This is the same bacteria we discussed a bit earlier that helps keep your fish tank clean and healthy. Live sand can be more expensive than regular sand, so if you’re on a budget, you don’t have to bother with it.

Although it is beneficial, you don’t need to start your fish tank out with live sand. That’s because bacteria are bound to start growing in your tank anyway, so you don’t really need to worry about buying live sand. It will take a bit longer, but you’ll get there eventually.

Note that if you’re in a hurry to set up your fish tank, it might be best to buy live sand. You only really need the bacteria to grow fast if you’re eager to fill your tank with new fish. If not, you can let the natural process take its time.

What Sand Is Best for Your Tank?

When it comes to types of sand to choose from for your tank, there are several options.

Before you decide, let’s check them out, so you know which will be best for your tank.

You need to consider the size of your sand grains (medium, fine, very fine), your fish, and the color you want.

If you want colored or non-standard sand, you don’t have that many options for grain size, but your fish tank will look unique.

Finer sand is more likely to get blown around by bigger fish and pumps, which could cause bare spots on the surface. It can also make your water cloudy. If you opt for coarser sand, you won’t get that ‘beach’ look, but the grains will stay in place better.

The type of sand you choose determines what you can and can’t add to your tank habitat. For example, if you want sand-sifting creatures like obies, you need a finer grain size to suit them.

Now, let’s look at the types of sand you can choose and how they’ll benefit your tank.


Aragonite sand is the most popular choice among fish lovers. It is most recommended for saltwater fish tanks and looks like regular sand. It’s fine-grained and consists of calcium carbonate.

This sand is great for maintaining your tank’s pH and contributes to stabilizing alkalinity and calcium levels.


Oolite, also known as Oolitic aquarium sand, is a spherical and fine type of aragonite sand. It is formed by ooids and is less than 2mm (0.08 in) in diameter. This sand helps to maintain stable pH levels in your tank.

Crushed Coral

As the name suggests, crushed coral isn’t technically sand, but it’s small enough to play the same role as sand does in a tank. It helps to improve the tank water’s pH and alkalinity levels. Crushed coral is often a good choice in saltwater tanks.

Traditional Sand

This is the most obvious and common choice for sand, and it’s perfectly suitable for most situations. Traditional sand serves its purpose: it is a good substrate and looks great in any tank.

Black Sand

how much sand for 55 gallon tank
Tahitian moon sand, better known as black sand, is formed through volcanic activity. Plants grow quickly in this sand, and if you need gravel but want sand, this is a great alternative. Black sand also promotes the growth of healthy bacteria.

White Sand

If you’re looking to have a fish tank with a bright look, white sand could be just what you want. However, this kind of sand can get covered in bacteria and clogged with dirt. It isn’t likely to remain white for very long.

Despite losing its bright color, the sand is still great for your tank’s health because it promotes bacterial growth.

Pink Sand

This is a mixture of aragonite sand and the shells of a sea creature and has the same benefits as aragonite. However, some brands of pink sand can help prevent algae growth and don’t have to be replaced.

For the most part, your choice of sand for your fish tank will depend on the look you want to achieve. There isn’t really a ‘best’ type of sand because none of them stand out for any particular reason.

The Depth of the Sand

Your sand bed can be shallow or deep. Shallow beds are between 1 and 2 inches (2.54 and 5.08 cm) deep, while deep beds can go up to 6 inches (15.24 cm).

It is important to remember that you will have to clean and maintain the sand with a siphon. So, shallow beds might be better for owners who don’t have a lot of time to maintain their fish tanks.

Shallow Sand Beds

With a shallow sand bed, you get a more natural appearance, and there is more space for water, fish, and plants. It is easier to clean and looks better in general.

However, if you want complex decorations and lots of plants, you need an arrangement with enough depth to anchor them.

Deep Sand Beds

If you have a deeper sand bed, you can add more decorations and plants to your tank, as the sand will provide adequate anchorage. However, deeper substrates can suffer from the buildup of carbon dioxide and methane.

However, you sort out this problem by stirring the sand. For this purpose, sand burrowers such as gobies, crabs, and snails will do just fine.

Having deeper sand beds also provides more room for microorganisms to grow. For a healthy tank environment, this growth is essential.

Calculating How Much Sand You Need

Now that you know the importance of sand in a fish tank, we can discuss how you’ll calculate how much you need.

Fresh Water Tank

We will use the following dimensions for this calculation:

12.25 in x 48.25 in (31.12 cm x 122.56 cm)

For a freshwater tank, you will have to provide sand based on the inhabitants. If you have small burrowing fish and few plants, 1 inch (2.54 cm) of sand should be enough. If your burrowing fish are large, you need at least 2 inches (5.08 cm) of sand.

You should have at least 1.5 lbs. (0.68 kg) of substrate per gallon for your tank. For a 55 gallon (208.20 liter) tank, that would mean 82.5 lbs. (37.42 kg) of sand.

However, tanks with unusual shapes may need less or more sand. In some cases, you will only find out how much sand you truly need through trial and error.

Saltwater Tank

Most saltwater tanks will do well with shallow sand beds that are only between one and two inches deep.

You may end up with a buildup of harmful detritus and higher nitrate and phosphate levels, though. That’s why you should clean the tank as often as possible.

As for how much sand you’ll need, at one or two inches deep, anything between 24 and 48 lbs (10.89 and 21.77 kg) should suffice for a 55 gallon tank. Again, this number can change depending on the shape of your tank.

If you want a deep sand bed, it should never be more than 6 inches (15.24 cm). This depth is more natural and has the most benefits, as discussed earlier. In this case, 143.66 lbs. (65.16 kg) of sand should be enough to get your tank filled with the desired depth of sand.

Note that if the sand you’re using is more refined, you may need more. For example, a 55 gallon tank with fine sand will need about 62 lbs. (28.12 kg) of sand for a two-inch substrate. For a 6 inch (15.24 cm) bed, you’ll need about 185 lbs. (83.91 kg) of sand.

How To Add Sand to Your Fish Tank?

Adding sand to your fish tank isn’t very complicated, but there is a right way to do it and a wrong way. We’ll discuss the right way, so you don’t even have to think of any other way.

First, clean the sand that you’ve purchased. Not many people realize it, but the dry sand you buy can be full of dust. If you put the sand with all that dust in your tank, your water will look ugly and cloudy. Plus, the dust could contain harmful bacteria that make your pets sick.

To clean the sand:

  1. Pour some of it into a bucket.
  2. Fill the bucket partly with water and stir the sand with your hand.
  3. Keep rinsing the water and stirring it until the water is no longer cloudy.

Then, follow these steps:

  1. If this is your first time setting up the fish tank, scoop the sand with a plastic cup and add it to the bottom. You mustn’t scoop and dump large amounts of sand in one area, as this might put stress on the glass and it can crack or break. Instead, add the sand in even amounts until it’s the depth you want.
  2. With an already setup tank, you need to scoop the sand in a bowl and lower it all the way to the bottom.
  3. Gently turn the bowl over as close to the bottom of the tank as possible. Work gently, and don’t just dump the sand. If you do, you’ll make the water cloudier than it has to be.

55 Gallon Fish Tank Essentials

how much sand for 55 gallon tank
If you want to have a 55 gallon tank, you need to know how to take care of it properly. There are a few essentials to have, or your tank won’t be a nice home for your fish.


You must have a filter installed on your fish tank to thoroughly clean the water. Without a filter, your tank will become toxic, and your fish can get sick and die. While biological filtration is great, it might not be enough for your tank water’s health.

A mechanical filtration system will go a long way towards removing debris from the tank. You can use a sponge filter, under-gravel filter, HOB filter, or canister filter. Your tank likely comes with one already attached. If not, you need to get one before adding your fish to their new home.

The Penn-Plax Cascade Canister filter is a great choice for big and small fish tanks.


Heaters are essential for freshwater and saltwater tanks. If you’re planning on having a cold water tank, you won’t need a heater.

You must ensure that the water’s temperature is perfect for the fish you want to add to your tank. If you want a community tank with different fish species, you’ll have to plan it well so that all of them are comfortable.


People often overlook the importance of lights in a fish tank. Different fish species prefer different intensities of light. As such, you need to create the best possible lighting that will suit your pets.

Like temperature, you should adjust the lighting to suit the fish. If you have different species, you’ll have to strike a balance or keep your fish in separate tanks.

If you plan to have live plants, the light in your tank will become even more important. Plants need light for photosynthesis, and yours may even need specific intensities and or wavelengths of light.

Fortunately, standard fish tank lighting is good enough for most setups. However, if you’re uncertain, do your research about the kind of light your fish and plants need.

Additional Equipment

Fish tanks need other equipment as well, such as fish feeders, pumps, and UV sterilizers. They’re not quite as necessary as lights and filters but can still make your fish tank a better place for your fish.

Cleaning equipment such as specific vacuums will also make your maintenance of the fish tank easier.

Best Fish Species for Your 55 Gallon Fish Tank

Chances are that you’ve already decided which fish species to add to your tank. But 55 gallons gives you a lot of space, and your tank might look a little bare once you’ve stocked it with your fish of choice.

Here are a few ideas to get you inspired if you need to add a few more fish to give your tank more life:


These fish come in many lovely patterns and colors. They are also available in many varieties and aren’t as territorial or aggressive as some other fish species. Just make sure that you don’t put too many males in your tank.

One male should be enough as the males don’t get along too well. The females are usually much calmer and tolerate each other better.


These freshwater fish are exotic and colorful. The Cockatoo and Peacock Cichlids are especially popular for adding a bit of color to fish tanks. However, they can be quite territorial and aggressive, so keep that in mind.

You can also consider other, smaller fish species such as Guppies, Zebra Danios, and Neon Tetras. They’ll add some color and life to your tank for sure.

Clown Fish, Mandarinfish, and Blue Tangs are pretty popular for saltwater tanks, as are Butterflyfish and Damselfish.

Blennies and Diamond Watchman Gobies are great for making sure the bottom of your tank is always busy. They also clean food from the sand, so your tank stays neat.

Other Options

You don’t have to limit your tank to fish. You can add small snails and shrimp to the ecosystem as well.

Plants are always good additions, too, which also add oxygen and shelter to the tank. Dwarf Hairgrass and Hornwort are great plant choices to get your tank started with.

How To Set Up Your 55 Gallon Fish Tank?

When you set up your 55 gallon tank, it is a good idea to start from the bottom and then work your way up.

Here are the steps:

  1. Add your substrate, which in this case, will be your choice of sand. Make sure your sand is clean before adding it to your tank.
  2. Add a layer of sand to your tank, and make sure to keep it even. Add as much needed sand as you’ve calculated and keep topping up until it’s as deep as you wish. This shouldn’t take too long.
  3. Once you’re happy with the sand, you can add your decorations after you’ve rinsed them off thoroughly. Make sure that you’re happy with the placement of all your decorations.
  4. It’s time to add the water. If you’re using regular tap water, treat it with a dechlorinator solution first to remove all the harmful chlorine.
  5. If you want a saltwater tank, you will have to add artificial saltwater by combining purified water and sea salt. Since the salt can take a while to dissolve, it might be best to leave it for a day before filling up your tank.
  6. Add all your equipment last. Every piece should come with installment instructions. If not, you can use the internet to find out precisely what you have to do. Make sure that you clean everything before you add them to the tank.

Cycling Your Tank

Fish waste causes toxic ammonia to be released into the water, which the bacteria in your tank can break down into something less harmful. So, you need to make sure your fish tank has the right bacteria before you add your fish.

This process is known as ‘cycling the tank.’.

You will follow the nitrogen cycle, which means one group of bacteria converts ammonia into nitrite and another group converts that nitrite into nitrate. While ammonia and nitrite are toxic even at low concentrations, nitrate is not.

Unfortunately, cycling your 55 gallon tank can take between two to eight weeks. Most of the process is automated, though, so you don’t have to do much.

This process is also known as ‘fishless cycling.’ It is unethical to do this cycle with fish in the tank because you actively expose them to harmful conditions.

Here are the steps:

  1. Start by adding an initial two to four parts per million of ammonia. After that, add one part per million every few days.
  2. Use a water testing kit to check your water levels and monitor the ammonia, nitrite, and nitrate.
  3. You should notice after two weeks that the nitrite levels go up. After ammonia and nitrate reach zero parts per million, you have finished the cycle, and you can add your fish.

Adding Your Fish

Once you have prepared your tank, you can start adding your fish. You shouldn’t add too many of them at once, or there will be too much waste for your tank’s bacteria to handle.

Here are the steps:

  1. Make sure your fish tank light is switched off. Let the plastic bag containing your fish float on the tank’s water surface for about ten minutes. This will let your new fish get used to the temperature.
  2. Add half a cup of the tank water to the bag every 15 minutes. Do this for an hour, and the fish will have a safe and comfortable transition.
  3. Use a net to remove your fish from its bag and release it into its new home. To avoid pollutants that can cause diseases, do not let any of the bag’s water enter the fish tank.
  4. Leave your tank’s light off for the first few hours, as the process can be stressful for the fish. Being in the dark will let them relax until they get used to their new home.

Final Thoughts

Now you know how much sand you need for your 55 gallon tank. All you need now is find the perfect fish for your tank and start preparing for their arrival.