Best Reef Sand Substrate – Review & Guide

Whether you are starting a new reef tank or rehabilitating an older established tank, the choice of the reef sand substrate that goes into your tank is as important as the marine animals that will inhabit the tank.

Before you decide on which substrate you want to use in your tank, you must educate yourself about the different options in substrates material that you will find available.  Not all substrates are the same.  There are different grades, types, sizes, and materials from which to choose.

Our Best Reef Sand Substrate list should help you gain this understanding and get you started toward making the best decision about which substrate fills the needs of your reef tank setup.

Reef Sand Substrate Reviews

CaribSea Arag-Alive Fiji Pink Sand

If you are starting a new reef tank, or rehabilitating an older tank, you can’t do better than starting with CaribSea Arag-Alive Fiji Pink Sand. This substrate has a soft pink color that blends well with any tank décor.

The massive amounts of surface area provide a home for the bacteria that already inhabit each bag of sand. These bacteria will go to work immediately, reducing the levels of nitrates and nitrites in your tank, meaning no more waiting before adding fish.

The grain size of this sand is large enough to prevent blowing around the tanks yet fine enough to allow creatures that like to burrow ample opportunity.  Sand moving fish will handle this sand easily.

The attractive color, bacteria cultures, and perfect grain size will enhance any tank.  From the first startup, CaribSea Arag-Alive sand will be at work, keeping your tank healthy and will keep on working without replacement.


  • Each bag includes a flocculant to reduce cloudiness in the water
  • Fine enough for sand shifting fish to handle but doesn’t blow and drift
  • Comes wet with seawater


  • The organic matter in the sand can cause problems in smaller tanks with proper filtration

CaribSea ACS00050 Aragonite Reef Sand

pH support in any tank is important.  The natural materials included in the mix of this substrate provide excellent pH balancing capabilities, and the live components will quickly help bring your tank water chemistry into line.  The soft natural colors provide a neutral background for your tank décor.

Along with the other natural materials, CaribSea Aragonite Reef Sand contains crushed coral and shells.  If you host burrowing creatures, this blend of sand and other natural materials is a perfect habitat. Your marine creatures will adapt quickly to this substrate.

Mechanically, CaribSea Aragonite Reef Sand works well with most reef tank filtration systems.  The size and mixture of materials combat the buildup of detritus that can become a problem in some tanks.

CaribSea ACS00050 Aragonite Reef Sand is an excellent choice as a foundation substrate for your reef tank.  It provides pH stability, excellent filtration characteristics, and a natural habitat for almost all types of aquarium inhabitants.


  • Very little silt. Water clears up quickly after adding it the tank
  • Great balance of fine and coarse material in one bag
  • Doesn’t move around the tank like other fine sands


  • Some bags may have large amounts of ultra-fine silt

CaribSea Seaflor Special Grade Reef Sand Substrate

Some reef tanks require a bit coarser material as part of the substrate.  CaribSea SeaFlor Special Grade Reef Sand Substrate fills the bill perfectly if you need larger grains for your reef habitat.

CaribSea Seaflor Special Grade Reef Sand helps mitigate pH problems in reef tanks as well as providing the perfect habitat material for larger burrowing reef tank inhabitants.  The slightly larger grains give these bigger fish more material from which to build their burrows.

CaribSea sands are free of impurities such as ash, metals, pesticides, and silica.  You can rest assured when using CaribSea products that the environment in your tank is safe.  This all-natural product is a clean and safe foundation for your reef environment.

The soft creamy color or CaribSea Seaflor Special Grade Reef Sand coordinates easily with any type or style of décor you want to put into your tank.  This sand also works with almost any kind of filtration system to maintain clean and balanced water quality.


  • Looks almost pure white under blue LED lights
  • Great balance of fine particles and bigger, coarser bits
  • Great for cichlid tanks


  • Does require a good washing to help with the cloudiness in the tank

Imagitarium White Aquarium Sand

If white on the bottom of your tank is your goal, then Imagitarium White Aquarium Sand should be on your list.   This reef tank substrate is a bright white and makes a perfect background for your tank décor. The brilliant white of Imagitarium White Aquarium Sand makes brightly colored reef fish seem to pop out of the thank.

Imagitarium White Aquarium Sand is a fine grain substrate that will settle well onto the bottom of your tank yet provide ample room for bacteria growth and excellent filtration characteristics.  This substrate makes the perfect planting medium for live aquarium plants.

One great advantage of Imagitarium sand is that it comes pre-washed.  Pre-washed substrate eases a lot of the setup work by almost eliminating the need to rinse your substrate before placing it in your tank.

Imagitarium White Aquarium Sand is easy on fish as well.  Fish with long or delicate fins will find this substrate a great habitat without ragged fin edges.  Imagitarium sand is a beautiful substrate for beautiful fish.


  • Brilliant white color for a pristine look in your tank
  • Comes pre-washed for easy setup
  • pH neutral to keep your tank in perfect balance


  • Some high-volume filtration system may keep fine particles stirred up in the water.

CaribSea Aquatics Eco-Complete Black Sand

If you run a brackish water tank and keep African cichlids, you won’t make a better choice than CaribSea Aquatics Eco-Complete Black Sand for your tank substrate.  The natural materials in this sand formulated to recreate that brackish water ecosystem in which cichlids thrive.

The physical characteristics of CaribSea Eco-Complete Black Sand maximize the available surface area for bacteria growth that promotes clean and healthy water quality.  Better water quality means healthier fish and less time maintaining your tanks.

CaribSea Eco-Complete Black Sand provides a mineral and biologically complete substrate. The minerals will help maintain pH as well as increase the mineral content of the water for the best fish environment.  The grain size of this sand provides maximum area for bacteria culture as well.

The black coloring of CaribSea Eco-Complete Black Sand is complimentary to any tank décor.  The black coloring sets off the colors of both fish and tank plants.  Not only is this sand attractive, but it works well with your filtration system to keep the water in perfect condition.


  • Non-magnetic so it won’t be attracted to pump impellers
  • Pre-washed for quick tank startups
  • Works well with other brackish water marine creatures


  • Doesn’t work well with under gravel filters

Nature’s Ocean No. 0 Bio-Active Reef Sand

Getting a reef tank up and running can be a dangerous proposition.  Nature’s Ocean No. 0 Bio-Active Reef Sand can relieve some of the stress of starting a reef tank because it starts working as soon as you put it into the tank.

The aragonite in this sand also helps maintain proper pH levels.  With both bacterial action and chemical action, Nature’s Own Bi0-Active Reef Sand works long term to keep the water quality in your tank in prime condition.

The physical properties of Nature’s Ocean Reef Sand promote maximum amounts of beneficial bacteria in the substrate.  More bacteria equate to better management of nitrates and ammonia that other methods for healthier fish.

As an addition to active tanks, Nature’s Ocean Sand brings all the benefits of aragonite sand and a material that settles quickly with little or no cloudiness.  The color blends well with other substrate materials for an attractive, clean look on the bottom.


  • Pre-washed for easy tank setup
  • Contains real marine shell pieces to help balance pH
  • Beautiful off-white color blends well into the aquarium décor


  • The fine consistency of this product can be a problem with high flow filtration systems

Brightwell Aquatics ABAKSUB1400 Kora Lagoon

Many aquarium operators employ a refugium or sump system as part of their water filtration and management.  The addition of a refugium requires a different approach to the substrate. Brightwell Aquatics Kora Lagoon sand is the perfect substrate for use in a refugium.

Brightwell Aquatics Kora Lagoon sand contains a balanced mixture tor aragonite and natural organic matter that perfectly simulates the lagoons that are often associated with the inside of marine reef structures.

Brightwell Aquatics Kora Lagoon is the perfect medium to recreate this lagoon environment.  Lagoons typically serve as the natural filtration system for a reef and provide homes for countless invertebrate and small fish species.

As part of a reef tank aquarium system, a lagoon type refugium can be an integral part of tank health and environmental quality.  The natural filtration process and the addition of more marine bacterial organisms ensure excellent ammonia and nitrate management.


  • The color of the sand is a pleasing wet sand hue
  • Provides a great medium for growing plants
  • Adds a massive amount of surface area for beneficial bacteria growth


  • Not suitable as a tank substrate
  • Needs to be rinsed thoroughly to prevent cloudiness in the water

Estes Marine Sand Black for Aquariums

Stoney River is the brand name for Estes Marine Sands.  Estes produces these sands in a variety of colors and sizes for most aquarium uses.   The Estes Stoney River sands are not live sands and are suitable for both marine and freshwater aquariums.

This sand might be considered a bit coarse for some applications.  The grain is about the size of coffee grounds and seems to be a bit lighter in weight than other aquarium sands.  The material used in the Stoney River products is non-toxic and pH neutral.

If you are growing live plants in your aquarium, Estes Marine Sand is a good choice.  The grain size and weight of the sand particles provide excellent anchoring for marine and freshwater plants.

The grain size of the Estes Marine Sand is well suited to growing bacteria colonies that help regulate and maintain water quality.  These bacteria colonies, combined with your mechanical filtration, will keep ammonia and nitrates at a perfect level, ensuring healthy fish.


  • Beautiful black color enhances the color of fish and plants
  • Settles well into the tank with little problem
  • Excellent medium for rooting plants


  • Ships dry and is dusty. Requires rinsing before introduction into the tank
  • May discolor the water to a certain degree but fades over time.

CaribSea Dry Aragonite Special Grade Reef Sand

Sometimes smaller grain sand is a better option for a substrate.  CaribSea Dry Aragonite Special Grade Reef Sand is an option if you want a smaller grain size in your tank.

CaribSea Dry Aragonite is a perfect balance of grain size and weight.  The grain is finer than most marine substrate, but it is large enough and heavy enough not to blow around in the water and get suspended.

The aragonite mixture in the CaribSea Dry Sand brings all the benefits of a natural marine substrate to your tank.  Large surface areas for maximum bacteria growth and the pH balancing qualities of calcium carbonite.

Dry sand does have advantages.  Dry sand substrate does not have the live bacterial components of wet sand.  Dry sand allows you to culture and grows specific types of bacteria rather than the catchall approach of wet sand.


  • No live bacteria allow specific bacteria to be cultured and grown
  • Finer grain settles into the tank well but is still heavy enough to be stable in the water
  • Natural pH balancing


  • Lots of dusty and requires good rinsing before being put into a tank
  • Can be too fine and may need to be mixed with coarser sand for best results

Nature’s Ocean Marine White Sand #0

Creating a natural environment in an aquarium reef system can be a challenge.  Nature’s Ocean Marine White Sand can be the first step in creating that natural environment.  Nature’s Ocean White Sand comes directly from the ocean floor with no other ingredients or additives

The source of this sand is direct from the ocean sand beds. Nature’s Ocean Marine White Sand provides natural carbonate hardness for pH management and marine trace elements that other sands may not include.  There is no more natural way to create a reef environment.

For added protection, Nature’s Ocean Marine White Sand is heat sterilized to provide a clean substrate.  Sterilization creates a perfect environment for culturing live sand in your aquarium.  You need not worry about what else might be growing in your live sand.

The grain size of Nature’s Ocean marine sand is perfect as a foundation for a marine aquatic system.  This size od grain provides maximum bacteria surface and excellent filtration characteristics.  Nature’s Ocean sand is fine enough to look natural yet large enough to be stable in the tank with very little drift.


  • Light and soft enough for fish with the most fragile fins
  • Bright white color shows off fish extremely well
  • Great filtration. My water stays crystal clear


  • It is so fine that vacuuming the bottom is a challenge.
  • Can take days for the water to clear after adding sand

Types of Reef Substrate

  • Aragonite – Aragonite is a primary ingredient in aquarium marine reef sand and is a carbonate mineral. The main source of this material in sands called aragonite is the shells of mollusks and other marine animals.  Most of the sand in the world’s oceans are made up of aragonite as countless marine creates, including corals, die, and their shells are break into finer and finer pieces.
  • Coral Reef – This material is much like aragonite. It shares many of the same traits and is often included in substrate blends with aragonite and other materials.  Coral reef will eventually stabilize your pH at about 7.6 and can be used in marine, reef and brackish water tanks.
  • Crushed Shell – Crushed shell material is typically much coarser than either aragonite sand or Coral reef sand. It is not uncommon to mix these materials to get a broader range of grain size in your aquarium substrate.  Crushed shell has the same characteristics and will produce almost the same results in pH and bacteria growth.
  • Manmade Materials – Some products on the market contain human-made materials. These may include glass, crushed gravel, and plastics.  Many of these materials are suitable for use in marine reef systems.  However, some of these substrate materials may contain dyes or coatings that can be harmful to fish.

How to Select a Reef Sand?

There are several things to consider when choosing reef sand.

  • What size aquarium do you want to use for your reef?
  • The type of filtration you will use in the aquarium
  • The type of fish you want to keep.
  • The size of the fish when they are fully grown.
  • The water requirements for the fish you intend to put into the aquarium.
  • The aesthetic you want to create with your tank décor.

Aquarium Size

The larger the aquarium, the more sand it takes to provide an adequate substrate.  Sand is heavy and can add a considerable amount of weight to your tank and the tank stand.  Larger tanks may require a layered approach with a coarser and lighter substrate on the bottom and a finer-grained material on top.  A layered substrate can add to the maintenance time since keeping a layered substrate can be labor-intensive.

Filtration Type

Some substrate sands are not suitable with under gravel filters.  Finer grained marine reef sands can be easily disrupted and blown about the aquarium if the flow tubes in the aquarium are too strong or too close to the surface of the substrate.  Some very fine grain sand can be sucked through the filtration system adding to problems with clogging and pump damage.

Types of Fish

Some types of marine animals need special types of substrates to flourish in captivity.   Burrowing fish need marine sand that is suitable for their size and habits.  Some shrimp can only exist with certain kinds and grades of marine sand.  You should make sure that your sand substrate is suitable for the species of fish that inhabit your tank.

Size of the Fish

You need to think down the road in planning your tank.   Knowing the eventual size of your mature fish can make a difference in the type of substrate that you put into your tank.  Typically, bigger burrowing fish need coarser gravel or sand.   Fish that will develop large, fragile fins need a softer, more forgiving sand.  Planning for the needs of mature fish can be challenging as their needs may change as they grow.

Water Requirements

Are your fish brackish water fish like cichlids or marine fish such as moray eels?  The natural environment of the fish you keep should determine the type of substrate that you use in your tank.  Different substrates will have different effects on the water, especially in managing pH, mineral content, and bacteria growth.  Matching the substrate that your fish would normally find in a wild environment can make a huge difference in the success of your aquarium.

The Aquarium Aesthetic

Last, but certainly not least, is the look you want to create in your aquarium.  The color, grain, and physical makeup of the aquarium substrate you chose will set the tone for your system.  The visual appeal of the aquarium is a major reason for keeping marine animals.  Aquariums tend to be soothing and calming when in a room.  Your enjoyment of your aquarium is as important as any other consideration.

Frequently Asked Questions about Reef Sand

How Does Marine Reef Sand Work?

Aquarium sands based on aragonite tend to be moderators of water pH.  Natural aragonite aquarium sands also provide many of the minerals necessary for supporting a healthy reef life.  These attributes contribute to the overall health of the system. Aragonite sands also contribute to system health by providing more surface area to which bacteria attach and form colonies.  These bacteria, predominantly heterotrophic, autotrophic, and chemolithotrophic strains, are essential to maintaining a healthy ecology in a marine reef tank.

Can Aragonite be used in a Freshwater Aquarium?

In general, yes, aragonite aquarium sand can be used in a freshwater tank.  However, there is a difference in the way aragonite sand is sold and delivered.  Some aragonite sands come as “wet” or “live” products.  These sands contain natural saltwater that preserves the living bacteria in the sand.   Putting this “living” sand in freshwater will kill the saltwater bacteria and produce problems in your tank.   Dry aragonite products do not have these living bacteria and are safe to use in freshwater aquariums.

Is Aragonite Compatible with Live Plants?

By all means!  Live aragonite sand already has an established bacterial culture that is plant friendly.   The dry varieties of aragonite, some of which come sterilized, can be used with live plants but need to have the bacterial cultures established to get the full benefit.  Fortunately, the live plants you introduce will probably have some of those bacteria with the roots which can jump-start your bacteria colony.

Is Crushed Coral Better than Aragonite?

Many purest advocate using crushed coral as the substrate for your reef tank.  Opinions vary, but in the long run, high-quality sand offers the same benefits as crushed coral without many of the problems.  Crushed coral tends to buildup detritus that is hard to remove.  Some marine creatures will work better with sand since they can turn the sand easier than crushed coral.  This turning by starfish and pods keep the sand fresher and cleaner.

How to Decide How Much Sand You Need?

In general, the recommendation is that you keep at 1-¾ inches of sand in the bottom of your tank and no more than two inches.  At this depth of sand, you will need approximately 1.5 pounds of sand per gallon of water in your aquarium.   If you have a 50-gallon tank, you should expect to need about 75 lbs of reef sand to have an adequate depth on the bottom of your tank.

You can of course go deeper than 2 inches but in most aquariums you aren’t gaining any additional benefit.You made need more depth if you keep large burrowing marine animals.  Larger marine animals that move sand as part of their normal routine may also require deeper substrates.

Some aquarists layer their substrate.  Deciding how much substrate for each layer is very much personal preference.  Some experimentation may be needed to determine an optimum depth for each layer of substrate you need.

When ordering your sand, you should also consider whether you are buying wet sand or dry sand for your aquarium substrate.  Packages of wet or live sand often include the weight of the water in the total weight of the packaging.  Water is heavy and can affect the quantity of sand you receive in the package.

For more information about aragonite-based aquarium sand and crushed coral substrate look at this video.

In the End

The goal is always, first and foremost, to keep your marine animals healthy and vigorous.  Many variables can affect the health and vitality of the creatures that inhabit your tank.

We hope this guide to reef sand substrate has helped you better understand the importance of reef sand and how better to choose.  Even if you don’t agree with our suggestions, or if you have experience with reef sand substrates, please leave your comments, suggestions, or experiences in the comment section below.

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