Choosing the best aquarium sand for your fish tank can depend heavily on the type of tank you own. Live sand, for example, contains marine bacteria and is only for saltwater tanks. Fine sand looks beautiful but may need more maintenance than coarser types.
We spent many hours assessing some of the best aquarium sand options and chose CaribSea Super Naturals Crystal River Sand as our top pick for freshwater tanks. And for saltwater, CaribSea Arag-Alive Fiji Pink Sand cycles a tank quickly without blowing about.
But there are other more budget-friendly options, along with finer sands for bottom-dwelling fish in our list below. And we’ve also put together a comprehensive guide on what to look for when choosing the best aquarium sand for your tank.
So let’s dive in and take a look!
- Best Natural River Sand: CaribSea Super Naturals Crystal River Sand
- Best For Budget: FairmountSantrol AquaQuartz Sand
- Best For Planted Tank: SeaChem Flourite Black Sand
- Best For Reef Tank: CaribSea Arag-Alive Fiji Pink Sand
- Best For Fish Only Saltwater Tank: Nature’s Ocean Bio-Activ Live Aragonite Sand
- Best For Natural Beach Look: CaribSea Super Naturals Moonlight Sand
Best Aquarium Sand Picks Reviewed
We’ve drawn on hundreds of combined hours of freshwater and saltwater knowledge to bring you the best aquarium sand options for your tank. This includes key factors like grain size, along with assessing dry sands and wet live sand options.
1. CaribSea Super Naturals Crystal River Sand
Photo: Amazon.com
- Sand & Tank Type: Dry sand, freshwater
- Grade: Medium to coarse (approx. 0.5 to 1.0mm grain size)
- Bag Weight: 20.0 lbs
- Color: Natural/ stone
- Key Features: pH neutral/ inert, no artificial paints or dyes, grain size reduces build-up of waste, includes BioMagnet clarifier
- Best For: Natural River Sand
This natural, light-stone-colored sand is inert and has no artificial dyes or coatings to affect your pH, general hardness (GH), or carbonate hardness (KH). So you won’t have to worry about it changing your tank’s water parameters or affecting your fish.
Crystal River consists of medium to coarse grains of approx. 0.5 to 1.0mm, which are similar to sugar crystals. This means fish waste and food sit nicely on top without getting deep into the substrate, making your maintenance easy as you can simply vacuum across the top.
And unlike very fine sand, the medium grain size of Crystal River means it doesn’t get too compacted. So you’re less likely to get low-oxygen areas developing which can lead to harmful hydrogen sulfide buildup. We still recommend you gently stir your sand every 2 weeks though.
Crystal River is one of the softest sands in the Super Naturals range, making it great for bottom-dwellers with delicate mouths like plecos. And while it’s quite pricy, the 20 lbs bag is plenty to create a 2-inch layer in a 10 gallon aquarium.
While a small number of users have reported this sand can cause cloudiness, we found the opposite, particularly if you use the BioMagnet clarifier that’s included. Overall the majority of owners praise this sand for its beauty and lack of cloudiness if you rinse it well.
2. FairmountSantrol AquaQuartz Sand
Photo: Amazon.com
- Sand & Tank Type: Dry sand, freshwater
- Grade: Medium, grade #20 (approx. 0.45 to 0.55mm grain size)
- Bag Weight: 50.0 lbs
- Color: Off-white, light tan flecks
- Key Features: pH neutral/ inert, odorless, natural and chemical free, uniform grain size
- Best For: Budget
Silica or quartz-based pool filter sand can be one of the best aquarium sand options if you want value for money. This 50 lbs bag of quartz-based sand will allow you to create a good 2-inch layer in a 30 gallon aquarium and is roughly 3 times cheaper than specialized aquarium sand.
Its off-white color with light tan flecks gives it the appearance of beautiful tropical sand. And as it’s natural and very soft it’s great if you have fish that like to forage like loaches or substrate-brooders like discus.
Pool filter sand is often very fine, but the AquaQuartz sand is medium grade #20 with a uniform grain size of approx. 0.45 to 0.55mm. This means it settles well without clouding up your tank or clogging your filter. But do position your filter intake 1.5 inches above the sand to be safe.
Although the uniform grain size helps waste settle on the surface, be aware that as with most pool filter sands you’ll usually need to vacuum it weekly. And as it can get quite compact, anaerobic pockets can build up. So it’s best you give it a gentle swirl as you clean it.
While some users highlight that this sand can look darker when you first receive it, it will clean up well after 2 to 3 rinses. Many owners give great feedback on this sand for its beautiful color, ability to settle, and suitability for bottom-dwelling fish.
3. SeaChem Flourite Black Sand
Photo: Amazon.com
- Sand & Tank Type: Dry fracted clay, freshwater
- Grade: Coarse (approx. 1 to 1.5mm grain size)
- Bag Weight: 15.4 lbs
- Color: Black
- Key Features: natural porous clay, supports planted tanks, pH neutral/ inert, not chemically treated
- Best For: Planted Tank
SeaChem Flourite Black Sand is one of the best aquarium sand options for a planted tank and is actually made from stable porous clay. The clay particles are very efficient at absorbing and holding nutrients from your water and supplying them directly to your plant’s roots.
It’s classed as coarse sand due to its grain size of approx. 1 to 1.5mm. But like other sands, these grains are small enough so waste material stays on the top where much of it can be removed by your filter. This makes maintaining your tank incredibly easy.
Unlike plant substrates made from compressed soil pellets, the stable clay particles won’t break down over time so you can go for several years without replacing it. And because it’s inert with no chemical coatings it won’t affect your water parameters or your fish.
Note if you plan to use this in a large aquarium it can get expensive, but the 15.4 lbs bag will easily provide a good 2-inch layer in a 5 gallon aquarium or a 10 gallon at a stretch.
As highlighted by several users, this substrate can be very dusty so make sure you rinse it 3 or 4 times before use. But overall SeaChem Flourite Black Sand receives great feedback from many owners for its vibrant look, ease of maintenance, and ability to help their plants thrive.
4. CaribSea Arag-Alive Fiji Pink Sand
Photo: Amazon.com
- Sand & Tank Type: Wet live aragonite sand, saltwater (reef tank)
- Grade: Coarse (approx. 0.5 to 1.5mm grain size)
- Bag Weight: 20.0 lbs
- Color: Natural off-white, some pink flecks
- Key Features: live aragonite sand, contains marine bacteria for tank cycling and biological filtration
- Best For: Reef Tank
CaribSea Arag-Alive Fiji Pink Sand is live aragonite sand for saltwater tanks, containing millions of beneficial marine bacteria. Along with your saltwater filter, these bacteria provide biological filtration keeping your ammonia levels down and reducing your maintenance.
The bacteria in Arag-Alive also jump-starts your nitrogen cycle in a new saltwater tank with ammonia levels and other key water parameters stabilizing in days rather than weeks. So if you’re just starting your saltwater tank you’ll be able to add your fish much quicker.
Fiji Pink is a coarse sand with approx. 0.5 to 1.5mm grain size, and you’ll be able to use it in a reef tank if the flow is not too high. For a higher flow reef tank, we’d recommend the Special Grade Reef Sand as its 1.0 to 2.0 mm grain size won’t be blown around by your wavemaker.
Despite Fiji Pink being coarse, it’s soft and small enough for burrowing fish like sand gobies to sift through. And as it’s aragonite sand it contains calcium carbonate which is great for supporting your corals’ growth.
The 20 lbs bag is enough to provide a 2-inch layer in a 10 gallon tank, but in reality, you’ll need more for a larger saltwater tank. And because it’s wet sand you use it straight out of the bag without any rinsing or preparation.
Note while Fiji Pink is a beautiful off-white color it’s not actually pink. There are a few flecks but in the main, it’s not really noticeable. Overall though, this sand gets high praise from owners for its smaller grain size allowing a beautiful smooth look without blowing around.
5. Nature’s Ocean Bio-Activ Live Aragonite Sand
Photo: Amazon.com
- Sand & Tank Type: Wet, live aragonite sand, saltwater (fish-only tank)
- Grade: Fine to Medium (approx. 0.1 to 0.5mm grain size)
- Bag Weight: 10.0 lbs
- Color: Natural off-white
- Key Features: live aragonite sand, fast tank cycling, contains marine bacteria for biological filtration
- Best For: Fish Only Saltwater Tank
An alternative aragonite sand for your saltwater aquarium is Nature’s Ocean Bio-Activ Live Aragonite Sand. Note again as this contains marine bacteria you can’t use it if you have a freshwater tank.
It’s collected directly from the ocean, rather than cultured, and contains over 10 million bacteria per pound. These live bacteria will instantly boost your tank’s nitrogen cycle, breaking down harmful ammonia and nitrites, and helping to reduce your tank maintenance.
Nature’s Ocean Bio-Activ also allows you to cycle a new saltwater tank around twice as quickly as it would usually take. But while the manufacturer highlights you can start adding your fish within hours, we prefer to leave it 2 or 3 days before adding fish.
This sand is finer than Arag-Alive Fiji Pink, with around a 0.1 to 0.5mm grain size, and will settle beautifully, but can very easily blow around. So while it’s fantastic for a fish-only tank, if you’ve got a reef tank with a higher flow then CaribSea Arag-Alive is your best option.
The beautiful off-white color will give your aquarium a smooth, tropical beach feel. But as it’s very fine, you’ll want to use about 2 lbs of sand per gallon. So you’d need about 80 lbs for a 40 gallon aquarium.
While some owners have highlighted this sand can be cloudy when first added to your tank, it clears within an hour or so. And many users have praised it for the beautiful smooth grain which is soft for fish like sand gobies, and the speed at which it cycled their tank.
6. CaribSea Super Naturals Moonlight Sand
Photo: Amazon.com
- Sand & Tank Type: Dry sand, freshwater
- Grade: Fine to medium (approx. 0.25 to 0.75mm grain size)
- Bag Weight: 5.0 lbs
- Color: Natural off-white/ very light tan
- Key Features: pH neutral/ inert, no artificial paints or dyes, soft and fine grain size, includes BioMagnet clarifier
- Best For: Natural Beach Look
CaribSea Natural Moonlight Sand allows you to create a beautiful beach look in a freshwater aquarium. While it’s not paper white, more of a very light tan, it’s one of the closest looks you can get to the tropical beaches of Sri Lanka or the Maldives.
Again, this sand is natural and completely inert with no artificial paints or dyes, so won’t affect your pH or water hardness. This can be important if you keep fish such as discus, that like soft water and are sensitive to pH changes.
While this sand can be classed as fine to medium with a grain size of around 0.25 to 0.75mm, in reality it’s very fine and ultra-soft. So it’s great if you have sand-sifting or burrowing fish like corydoras or loaches. It also tends to settle well and give your tank a beautiful smooth look.
But as it’s fine it can stir up easily, so we don’t recommend you use it in a saltwater tank with high flow. It’s best with an adjustable filter like a hang-on-back (HOB) that won’t disturb your water too much. And do ensure you mount your filter intake 1.5 to 2 inches above the sand.
As highlighted by several owners, this sand can stay suspended in your water column and clog powerful filters. But you can significantly reduce clouding by washing it thoroughly. Do this by rinsing in a bucket and repeatedly changing the cloudy water until it’s completely clear.
You should also gently stir the sand with your fingers weekly to stop anaerobic pockets where hydrogen sulfide could form. But if you follow these simple steps you can create a gorgeous beach look in your aquarium, perfect for bottom-dwelling fish!
What To Consider When Choosing The Best Aquarium Sand
There are several factors for you to consider when choosing the best aquarium sand for your fish tank. Let’s look at the most important ones below.
How Does Aquarium Sand Compare To Gravel?
Aquarium sand and gravel are the most common types of substrate for your fish tank. When choosing between them, firstly think about the type of aquarium you own. Many aquarists choose gravel for freshwater tanks, whereas sand is the best option for saltwater tanks.
Sand can work just as well in freshwater aquariums though, and you should also research your species of fish. Zebrafish, for example, prefer gravel over sand [1]. But if you plan to keep substrate-brooding freshwater fish like discus, sand is the better option [2].
Advantages Of Aquarium Sand
Using the best aquarium sand in your fish tank can bring with it several advantages:
- Natural: Aquarium sand can give your tank a similar look to the silt-covered stream beds of many natural aquatic habitats. It usually has no coating or sealants meaning it won’t bring harmful chemicals into your tank.
- Versatility: If you prefer a themed look, nowadays the best aquarium sand comes in a wide range of colors and styles.
- Great For Burrowing Fish: Aquarium sand is best if you keep burrowing fish with delicate barbels, like the dojo loach [3], as there are no edges to cause damage.
- Easier Cleaning: As sand particles are small it’s more compact than gravel. This means uneaten food and feces will sit on the top and can be easily vacuumed.
Disadvantages And Issues With Aquarium Sand
As sand is so fine it can stir up and make your water cloudy which can clog your filter. To prevent this, make sure your filter’s intake is positioned at least 1.5 inches above your sand. Be careful to vacuum just above your sand too, rather than pushing your vacuum into it.
Because sand compacts down it can lead to poorly oxygenated pockets. This can allow anaerobic bacteria to colonize and produce hydrogen sulfide, which you may notice by the smell of ‘rotten eggs’ or by areas of your sand turning black.
Hydrogen sulfide can be very harmful to your fish [4]. So to prevent these ‘dead zones’ from occurring in your tank, swirl your sand very gently, particularly under ornaments, at least every two weeks.
Is Sand A Good Substrate For Live Plants
Aquarium sand can be an excellent substrate for live plants, but in a similar way to your fish, it can depend on the species. For example, the common aquarium plant Rotala rotundifolia has shown similar growth levels in both gravel and sand [5].
Like gravel, although sand provides a good anchor for your plants it doesn’t contain any nutrients. So if you plan to grow live plants in your sand you’ll usually need to provide a fertilizer like root tabs.
When choosing sand for your plants you should make sure it’s coarse enough. Not only will this reduce anaerobic pockets, but it helps the roots penetrate the substrate as it’s slightly less compact.
What Type Of Aquarium Do You Own?
If you own a freshwater tank you can choose from a range of substrates including aquarium sand and gravel. You can even choose active soil-based options to alter your pH for certain fish or shrimp.
But for a saltwater tank, the best aquarium sand is always the preferred option. There are 3 main types for saltwater tanks. Whilst you can use these interchangeably, some are better for fish-only tanks, and some for full reef tanks with corals.
- Oolite Sand: Oolite is an ultra-fine grade marine sand that is usually better for fish-only saltwater tanks. Whilst it allows you to build beautiful dunes and gives the look of a tropical sea bed, it blows around very easily.
- Crushed Coral: While sometimes categorized as aquarium sand, crushed coral is actually made up of larger particles of crushed coral skeleton. It’s a good substrate reef tanks, where a high flow is needed for corals.
- Aragonite Sand: Aragonite is the most common of the saltwater sands and, like crushed coral, is made up of calcium carbonate. It’s the best aquarium sand for many marine tanks and allows fish to burrow without blowing around like oolite.
Fish Breeds That Prefer Aquarium Sand Substrate
There are several species including substrate-brooding and bottom-dwelling fish that prefer aquarium sand. Whilst it’s important you research your particular fish, here are a few common freshwater species.
- Loaches: The Kuhli Loach is a common freshwater bottom dweller than does well with sand, as it prevents it from damaging its delicate barbels as it sifts for food.
- Plecos: Plecostomus catfish are herbivorous and great for keeping your tank clean as they will eat any algae they find. Some plecos can grow very large though. The Gold Spot Pleco, for example, can grow up to around 9 to 12 inches!
- Corydoras: Cory catfish, such as Sterba’s Cory, are another bottom-dwelling species that prefer sand as again it allows them to forage without harming their mouths.
- Guppies: Aquarium sand is undoubtedly the best substrate for guppies. While wild guppies occupy a range of habitats in places like Trinidad and Tobago, many of these are naturally sediment laden with a similar sandy substrate [6].
What Are The Main Types Of Aquarium Sand?
Whilst there are several different types, the best aquarium sand broadly falls into the categories below.
Specialized Aquarium Sand
Although often expensive, one of the best aquarium sand options you can choose is specialized aquarium sand. Not only are there many different types and colors, but you can find them to suit specific fish or do certain jobs in your fish tank.
For example, specialized aquarium sand can come in a range of grade sizes. Whilst you usually want to use medium grade, you can find fine grain sands to suit burrowing fish. Most sands are inert so you know they won’t affect your pH or other water parameters.
You can also find specialized aquarium sands, like those made from crushed coral, that are designed to raise your carbonate hardness (KH) and stabilize your pH. This can be useful if you own a brackish or saltwater aquarium.
Live Sand Containing Bacteria
A type of specialized aquarium sand, live sand is one of the best aquarium sand options if you’re starting a new saltwater tank. It’s made up of natural reef sand harvested directly from the ocean, or coral sand that’s been cultured with bacteria.
Live sand such as aragonite is biogenic, meaning it’s made by living organisms [7]. These bacteria and other microorganisms help balance the water chemistry in your marine tank. Unlike dry sands, it’s shipped wet to support the bacteria during transit.
Note that live sand is marine-specific as the bacteria and organisms contained within it are specifically designed to support saltwater tanks. You should not use live sand if you own a freshwater tank.
Pool Filter Sand
Silica or quartz-based pool filter sand can make a fantastic, inexpensive substrate for your aquarium. These sands are usually off-white in color and are beautiful when aquascaped. They are also inert and won’t affect your water parameters.
Bear in mind though, that as pool filter sand can be fine it needs to be kept clean, so be prepared to vacuum it at least once a week. You are also limited in color with pool filter sand, so if you want darker or colored options, specialized aquarium sand is better.
Clay Sand
Often better known as clay gravels, these are specialized substrates made from broken-up (or fracted) clay. Manufacturers usually categorize them as sand when they have been broken down to a small enough grain size, often below around 1.5 mm.
Clay sand is a particularly good substrate if you plan to keep live root-feeding plants and you want the look and feel of sand. As it’s porous, it will absorb nutrients from your water column and deliver them directly to your plant’s roots.
Types Of Sand To Avoid
With the exception of pool filter sand, it’s generally best to stick with specialized aquarium sand in your tank. Here are some sands you should avoid in particular:
- Artificial Sand: These sands are often made from industrial waste rock granules, but can be processed with artificial dye and sealants. These chemicals can cause issues with your tank’s water parameters and be directly harmful to your fish too.
- Play Sand: While some aquarists use play sand we wouldn’t advise it. Play sand is indeed inert, but it isn’t cleaned and processed in the same way as aquarium sand. You could bring harmful bacteria into your tank which could cause disease.
- Building Or Blasting Sand: Similar to play sand, building and blasting sands should be avoided as they can also harbor harmful bacteria.
Other Factors When Choosing The Best Aquarium Sand For Your Fish Tank
Before making your final decision on the best aquarium sand for your fish tank, take a look at these other factors to consider.
Grain And Particle Size
The best aquarium sand is often medium-grade with a grain size of roughly 0.5mm [8]. Medium grade means your sand particles are small enough to stop too much waste from getting into the substrate but large enough so it doesn’t become too compact.
You can also use fine-grade sand around 0.25mm which is great for burrowing fish, but make sure you prevent anaerobic pockets by gently raking your fingers through weekly. Coarse-grade sand with around 1mm grain size can be good for plants to allow their roots to penetrate.
In reality though, even the best aquarium sands will have a slight range in grain size so these numbers are a guide. Generally, while fine-grain sands look smooth and beautiful they can take more maintenance. And do avoid them with a high-flow tank as they will easily stir up.
How Much Sand To Add To Your Aquarium
In a smaller 5 gallon tank or nano aquarium, you may be able to use 1-inch of sand at a minimum. But in most cases around 2 inches is more appropriate. This is also the minimum depth you should use to give live plants a good anchor.
If you own a larger aquarium you may even want to increase this to 3 or 4 inches, particularly if you have burrowing fish like eels or loaches. Just bear in mind you’ll need about 1.5 lbs of sand per gallon. So for a 30 gallon aquarium you’ll need 45 lbs of sand.
Sand Color And Look Of Your Tank
There are many different types of sand and colors allowing you to create almost any type of natural or themed tank. You can find light and dark neutral sands for a natural look, or bright colors and even sand with fluorescent highlights for GloFish!
In most cases, you can choose the best aquarium sand to suit your tastes, but you should still research your fish. Some species, like saltwater sand gobies, camouflage themselves with their background so a natural look is better for them [9].
You should also think about how your choice of sand will highlight your fish. Highly colorful, or multi-colored fish such as the Peacock Gudgeon can look great against lighter sand. But be mindful that lighter sand needs frequent cleaning to keep it looking pristine.
Quality And Price
When choosing the best aquarium sand one of the ways of ensuring quality is to opt for specialized aquarium sand from a reputable brand. We only recommend these sands, along with pool filter sand, as they’ve been fully cleaned and treated for aquarium use.
The price of specialized aquarium sand can vary, with saltwater live sands often working out as more expensive. A good exception for freshwater tanks is pool filter sand. A 50 lbs bag can be around $25, which is often about half the price of aquarium sands.
Setting Up And Maintaining Your Aquarium Sand
Using the best aquarium sand in your fish tank can be one of the easiest substrates for you to maintain, especially if you set it up correctly.
How To Add Sand To Your Aquarium
Whilst aquarium sand is cleaned and treated, you should always thoroughly rinse dry sand before using it in your fish tank. But for a saltwater tank, if you are using live sand do not rinse it as this will remove the cultured bacteria.
Using a bucket you’ve specifically set aside for your aquarium, fill it half full with sand, then with water to the top. Stir with your hand and the water will become cloudy. Repeat until the water is completely clear, before adding it to your tank.
To stop your sand from stirring up as you add the water, place a large tray on top of the sand. Then carefully add the water on top of the tray to slowly fill your tank.
How To Maintain Sand In Your Aquarium
As many of the best aquarium sand options are medium-grade and have a similar degree of coarseness, the amount of maintenance they need is similar. Generally, you’ll need to vacuum your sand at least every two weeks in line with your aquarium maintenance.
If you use finer, lighter sand like pool filter sand, you may need to vacuum it more regularly at around once a week. And don’t forget to gently stir your sand every 2 weeks to prevent anaerobic pockets from occurring.
Our Verdict
When choosing the best aquarium sand for your setup some of the main factors to consider are your tank type and the grain size.
CaribSea Super Naturals Crystal River Sand is perfect for freshwater tanks as its medium grain size means waste sits on top helping to reduce maintenance. For a cheaper option, FairmountSantrol AquaQuartz pool filter sand is great for bottom-dwellers.
For saltwater tanks, CaribSea Arag-Alive Fiji Pink Live Sand is our top pick as it provides beneficial marine bacteria to kick-start your tank, and its grain size means it won’t get blown around a higher-flow saltwater aquarium.
FAQs
Here are the answers to some of the most frequently asked questions when it comes to choosing the best aquarium sand for your tank.
Can I Use Pool Filter Sand In My Fish Tank?
Yes! Silica or quartz-based pool filter sand is an inexpensive and beautiful-looking substrate that’s soft and great for bottom-dwelling fish.
How Should I Add Sand To My Aquarium?
Once you’ve washed your aquarium sand add about a 2-inch layer to the bottom of your empty tank. Place a large, thin tray on top and gently pour on the water to avoid stirring up your sand.
Why Is My Aquarium Sand Turning Black?
Areas of compacted sand can lead to pockets of low oxygen developing. Anaerobic bacteria can colonize here and produce hydrogen sulfide, which is toxic to fish and can turn sand black [10].
Is Aquarium Sand Difficult To Maintain?
Aquarium sand is generally easy to maintain as uneaten food and waste tend to sit on the surface rather than getting into the substrate, where it can be easily vacuumed away.
