Best Aquarium Substrate (Review & Buying Guide) in 2019

We humans have gone far from our roots of nature where we used to dive in and marvel at the scenic beauty underwater. Nowadays, the only way we can access that pleasure is through small glass boxes which hold aquatic plants and animals inside clear blue water. Aquariums not only add a soothing aesthetic value to our abode but also encourage affection for animals and nature in the young family members.

However, taking care of these aquariums and decorating them need regular supervision. Since the substrate is one of the first things which go into the aquarium, selecting it is an important step. To make the process easier for you, here are ten of the best aquarium substrates as picked by our substrates.

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Best Aquarium Substrate Buying Guide & FAQ

Things to Consider When Buying Aquarium Substrate

  • Type of aquarium inhabitants

Firstly, you need to ask yourself, “Who are the inhabitants of your aquarium abode?” If it contains plants, you should choose a substrate that provides the essential nutrients for their healthy growth. It is recommended to include those nutrients inside the gravels instead of the water column since roots are the main medium for plants to obtain those minerals. The substrate of a planted aquarium should have two layers – a lower one full of nutrition and an upper one of regular gravel or sand to prevent wash-out.

aquarium substrate

If the aquarium is full of fish only, the substrate must allow colonization of beneficial bacteria. The substrate layer should be shallow enough to prevent the food particles from sinking into a less oxygenated area since that can eventually result in toxic hydrogen sulfate. For marine and reef aquariums, you should introduce enough calcium and magnesium to raise the pH level high enough.

  • Type of water

There are different substrates available for different kinds of ecosystems. The one made for freshwater environments cannot be used in the saltwater environments. So check through the information of the substrate you selected to determine what kind of water it is made for.

  • Required amount

The right amount of substrate to put into the aquarium depends on its capacity or volume. For example, if a fish tank has 55 gallons capacity, its gravel layers should be about 2 inches deep. If there are plants involved too, a nutrient-rich layer of 1 inch can be added underneath the gravel layer. For bigger aquariums, the gravel layer can grow up to 3 inches.

  • Particle size

Gravels and other particles of substrates are mainly available in two sizes – fine and large. The finer gravel is meant to bring in the natural aesthetics to your aquarium and imitate the natural habitat for the fish. Larger gravels, on the other hand, are found in a wider variety of colors, giving you the option of playing more with the decoration. Some of them even glow in the dark making the whole setup much more fun than usual.

Larger gravel substrates will need more frequent cleaning since the unconsumed fish food deposited in their large gaps can turn toxic after a while. The finer gravels, on the other hand, need to be loosen up more often because they tend to compress together creating tank areas with the trivial amount of oxygen.

  • Color

When it comes to colors, you can choose among many but make sure none of them has actual paint colors on them. The paints can be nibbled on by the fish and cause it pain. If you want to take the safest road, choose the natural looking gravels which is the most comfortable for these fish.

  • Quality

The gravel quality should be smooth enough and without any sharp edges which can hurt the fish. So before settling on a substrate, run your hands on its sample and figure out if they feel smooth enough or not.

  • Water reactivity

The amount of required pH level in a tank varies depending on its residents. Certain fish species like African cichlids would require a higher pH level than usual. So aquariums with this type of aquatic creatures will need a substrate that buffers water like crushed coral. In contrast, species like angelfish need a lower pH level and thus substrate like peat moss is used in the system.

Benefits of Substrate in Aquarium

  • Plant growth

Most of the substrates are rich in nutrients which are beneficial for plants. They also improve the overall environment of the tank.

  • Stable position

It is hard for plants to hold onto the glass surface of the aquarium. So this substrate provides them with a better and more stable platform to stand on.

  • Pollution prevention

Substrate prevents pollution by keeping the fish waste and food waste at the bottom instead of floating around in the water.

  • Fish comfort

A glass surface would not feel familiar to the fish. Instead, a substrate layer mimics the natural habitat for them raising their comfort level.

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Types of Aquarium Substrate

  • Sand

Sand is the best substrate for a beginner since all fish love to dig and bury it. This makes cleaning much easier since dirt particles land on its top instead of getting lost in the grains.

  • Gravel

Aquarium gravel has smooth edges and thus make a comfortable substrate for fish lives. They come in varying size and colors to customize the tank’s appearance.

  • Crushed Coral and Aragonite

They both raise pH level in the aquarium and can bring the saltwater vibes to a freshwater environment. Crushed coral needs frequent vacuuming since its light color cannot hide dirt and debris very well.

  • Others

The planted tanks may utilize Fluorite, Laterite, EcoComplete, Aquasoil and similar substrates for nutrition and nourishment.

substrates for aquariums


Q:  What is aquarium substrate?

A:  An aquarium substrate is simply the substance placed at the bottom of an aquarium for both aesthetic and functional purposes. It has the power to influence the filtration, water chemistry, and health of inhabitants. A substrate can also affect the comfort level of aquatic creatures living in the tank by its color and texture.

Q:  How much substrate should I use for my aquarium?

A:  Typically, about 1 pound of the substrate is needed per gallon if you wish to form a one-inch bed in the rectangular aquarium. Also, 5 pounds of gravel, 6 pounds of dry sand and 8 pounds of wet sand are an ideal combination to form a one-inch substrate bed inside a 10×10 inches tank.

Q:  How to set up substrate for a planted aquarium?

A:  Firstly, lay down a strong sustainable foundation with a mineral-rich substrate after rinsing it. Then install filter and heater after filling up the tank with dechlorinated water. If you wish to adjust the pH level, use a water conditioner. Add a plant lamp for better growth of the aquatic vegetation. Keep it this way for 2 to 3 weeks before introducing plants and fish here.

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Q:  How should I clean my substrate before I add it to my tank?

A:  To prevent the tank water from getting cloudy, wash the dusty gravels or sand thoroughly. Put a small amount of the substrate in a clean bucket and spray water through a hose. Pour out the dirty water every time you are done washing a batch.

Q:  How can I keep my substrate clean?

A:  First of all, unplug all electrical components included like heater, filter, and pump. However, there is no need to displace the fish, plants and other decorations of the tank. Pick your cleaning tool of choice – a thick aquarium siphon for larger tanks or a plastic flexible tube for smaller ones. Put a bucket below the tank to hold in the old water. Submerge one end of the vacuum inside the aquarium while placing the other end in the bucket. Use your thumb to stop the water flow whenever necessary. After getting rid of all the dirty water, read the tank’s temperature and make sure the new water matches this temperature to not alert the fish.

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Q:  How often should I change aquarium substrate?

A:  Substrates which increase the pH level in water should be changed every few months to a couple of years. Clay substrates like Aquasoil need to be changed every 3 to 4 years. Gravels and sand don’t need to be changed since they are almost neutral. The plant-based substrates will need frequent changes to ensure proper nutrition and nourishment.

Q:  How deep should my silver sand be?

A:  If your tank has live plants, the depth of silver sand should be from 1 inch to 1.5 inches. If there is no live plant, it can go below 1 inch. A layer deeper than 2 inches can cause a build-up of toxic anaerobic bacteria.

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Q:  Can I use a mixture of grain sizes?

A:  A mixture of different sized grains can be used if you want a natural or colorful look in the aquarium.

Our Top Pick

According to our research, Carib Sea Eco Complete Planted Black Aquarium Substrate has turned out to be the best aquarium substrate. This freshwater black substrate has a highly porous structure and is rich in the essential minerals. It encourages strong plant growth by providing them with nutrients through roots and also converts fish waste faster into plant food using the heterotrophic bacteria.


  1. Step-by-step Guide to Setting Up a Planted Aquarium, LiveAquaria
  2. All You Need to Know About Tropical Aquarium Substrates, Tropical Fish Site
  3. Sand In Your Tropical Fish Aquarium, Tropical Fish Forums
  4. How to Clean Aquarium Gravel, wikiHow
Olivia Williams
Olivia is our head of content for, mum of one and a true animal lover. With 12 different types of animal in her family, it's never a dull moment. When she isn't walking the dogs, feeding the cats or playing with her pet Parrot Charlie, you will find her product researching and keeping the site freshly updated with the latest products for your pets!