Choosing The Right Sand For Your Freshwater Aquarium

When you’re establishing a freshwater aquarium – or looking to improve the one you’ve already got - then choosing the right kind of sand is an important part of the process.
But how do you know which sand is right for you?

In this article, we’ll look at some of the key advantages and drawbacks to using freshwater aquarium sand.
We’ll also review five products that can help you choose the right sand for your freshwater tank.

When it comes to aquarium substrates, there are different schools of thought about what’s best.
Some aquarists swear by gravel, as it has largish holes in between the granules, meaning water can flow more freely through it and there’s less opportunity for “anaerobic dead zones” that can lead to microbial growth.
Others prefer crushed coral, but be aware that it will raise the pH in your aquarium, so it’s not a good choice for fish that prefer water with a low to neutral pH.
Others swear by sand, arguing that it’s more natural and that the smaller gaps between each grain actually limit the bacterial growth that can accumulate from debris.

Ultimately you should read up on the behaviour of your fish and their natural environment. This will help you choose a sand that’s right for them, most importantly, as well as what’s right for you.
As an additional benefit, when these species dig or stir the sand, it also moves the substrate around, aerating it and ensuring the sand is kept well mixed.

There are a range of benefits to using sand as the substrate in your aquarium.

Many freshwater fish nose or sift through their sand to look for food, or they like to dig into it or makes “nests” as part of their natural behavior – for example goldfish, certain cichlids and loaches, or bronze corydoras as well as many others.
These species will appreciate a sandy bottom as they can create piles and slopes that aren’t possible with even the lightest gravel.
It will also be much gentler on their sensitive barbels, as it closely resembles their natural habitat.
As an additional benefit, when these species dig or stir the sand, it also moves the substrate around, aerating it and ensuring the sand is kept well mixed.

Apart from being a natural material that won’t introduce chemicals into your tank, sand also looks natural.
You can achieve a beautiful look in your tank by using sand to mimic the home environment of your species.
When you combine sand with a planted aquarium, the effects can be almost indistinguishable from a stream or pond in nature.
Sand works the way you’d expect - a light-coloured natural sand will catch the light and add brilliance to your aquarium. In contrast, a dark or black sand can have high drama and visual impact – your coloured fish will look stunning swimming against a black base.

Sand can change the look of your tank in an instant.
If the natural effect isn’t your style, you can choose from hundreds of coloured sands that make your tank bright and attractive.
These days you can buy sand and gravel in many different variations – coloured, natural, coated, fine-grain – the list goes on.
Watch out for those that are chemically coloured as this can introduce foreign substances into your tank water.
It’s a good idea to buy specialty sand from specialty providers who understand what’s needed for healthy tanks and fish.

Using sand in your aquarium can help make your cleaning duties easier, as it doesn’t let waste filter down between the particles as easily as gravel or crushed coral, for example.
This keeps debris on top, and if there is sufficient water movement in the tank, the waste will be caught and removed by the aquarium filter.
If your tank has less water movement, you can capture the waste with a weekly vacuum clean while you’re changing the water.
The downside is that waste can become visible very quickly, so your tank won’t look its best if you aren’t cleaning it regularly!

As sand is a fine material, you need to be aware that particles of sand can easily become trapped in your filter. Be careful not to stir it up too much when you’re changing the water, cleaning the tank or adding new features such as plants, rocks or ornaments.

Sand can also become compacted if it isn’t being regularly sifted or dug through by your fish. This can make it tough on any plants you have in the aquarium, as their roots can suffer and could also have difficulty penetrating through the sand. You might need to stir things up yourself every now and again – remember to watch out for your filter when you do this.

When you use sand as a substrate there is also a low risk of toxic gas pockets developing.
This is something that usually occurs when cheap play sand has been used, but not exclusively.
The toxic gas pockets form when there isn’t enough space between the grains of sand for oxygen to get through entirely, and the lack of oxygen allow small pockets of bacteria to grow.
When the pockets are disturbed, they can give off toxic hydrogen sulphide gas (also known as rotten egg gas).
This not only smells horrific, it can also kill your fish.

There are three common kinds of sands you can consider for your aquarium:

Can you add sand directly into your aquarium?
The short answer is no, even if you’ve bought a high-quality sand from an aquatic supplier or pet store. You must clean it first.

Cleaning sand is easy.
Use a completely new bucket and fill it to about halfway with the sand.
Now add water right up to the brim.
Stir everything around inside with your hand, so that any extra particles of dust or dirt are loosened from the sand grains.
The water will become cloudy – tip it out, being sure not to lose any of your precious sand in the process – and repeat the process until the water runs clear.
You can also try running a hose into the bucket continuously while you’re stirring.

When you add the sand into your empty aquarium, just spread it along the bottom.
The tricky part comes when you add the water.
You don’t want to accidentally ruin this substrate and stir everything up!
A good method is to put a dinner plate on top of the sand, and gently pour the water over just the dinner plate, so that the aquarium fills slowly.
You will still get sand floating up through the water, so be sure not to add anything else until it has settled and the aquarium is completely clear again.
This could take hours, days or a month.

Check out this handy video tutorial that shows you how to clean sand and then add it to your aquarium.

In this section, we’ll review five sands that can help you to build a beautiful aquarium that also functions well and supports your fish.

If you’re a beginner aquarist and you’re looking for an easy, failsafe option, then this Pool Filter Sand by Fairmount Minerals could be a good option for you.
The sand has a strong following amongst aquarists, as it’s a high-grade, 100% regular sand that is chemical-free.
It’s also cheap and easily available at pool stores or online.

This kind of sand has an extremely uniform particle size that ranges between .45 and .55mm.
That means it’s good and dense – it will settle down quickly into the base of your aquarium and it won’t easily get sucked into your filter.
This density also makes it a good choice for fish that like to sift through sand (eg goldfish) as it sinks back down easily after they’ve snuffled through it.

One bag will give excellent coverage in a 50-gallon tank. It has a bright, white colour with some specks of black and brown.
Although it’s listed as ready-to-use, remember that those instructions are for pools, not aquariums.
Always make sure to wash your sand before use.

Another good option is traditional play sand – the kind you find in sandpits and sandboxes all over the world. It’s ubiquity means it’s very easy to find: in hardware stores, pet stores, aquarium stores and online.

This children’s play sand by Brookstone is a good option for an inexpensive aquarium set-up. It’s an excellent quality play sand, offered by a reputable company. As it’s specially manufactured for children to play with, it’s completely non-toxic and safe for your aquarium.

One great bonus feature is that it comes in several different colours including natural, blue, yellow, purple and red. So if a technicolour aquarium is what you’re after, this could be a great option.

This sand clumps easily, so be aware of the potential for compacting, which could make it difficult for plants to grow and for your fish to sift through it.

For aquarists who are looking for high-impact visuals, this dramatic black natural Tahitian silica-based sand can provide an extraordinary and beautiful contrast to your fish and plants.
The colour is deep, rich and perfectly black – not greyish like some other brands.

You might think sand has to be dyed to create this colour, but one excellent feature of Carib Sea Tahitian Moon Sand is that no dyes or paints are used in its manufacture. You can use this in saltwater tanks as well as freshwater.

The sand has a beautiful velvety look and happily supports plant life as well as aquatic. Note though that it’s quite light and fine, so it will take a while to settle once you’ve added it to your aquarium. Be sure to let it settle completely before you add any fish. One 20-pound bag should provide plenty of coverage for a 50-gallon tank.

Be aware that this sand will require extensive cleaning before you can put it into your aquarium. A small number of aquarists have reported that they have lost fish due to cloudy water which can result from sand that isn’t cleaned sufficiently or hasn’t entirely settled.
Another customer claimed that their batch of product leached ammonia into the water – although the product manufacturer states that it is pH neutral - so it’s a good idea to check the pH before adding your fish, and to check it regularly afterwards.

To clean this sand effectively, it’s recommended that you do this outdoors. Allow a hose to run over it constantly while you’re handwashing it, until all the dust, debris and excess colour has been removed.
It could release some residue during the process, so it’s a good idea not to use your home bathtub or sink for this task!
Don’t give up before the sand is literally squeaky clean – it may take you longer than you were hoping for, so ensure you put enough time aside.

For aquarists who want to plant out their aquariums, Flourite Black Sand offers a great option.

This is technically a porous clay sand, and one of its best features is that it’s specially designed to support plant life.
It combines the dramatic visuals of black sand with a more appropriate particle size, giving it a two-in-one bonus.

However, this sand is extremely fine and it will require an extensive clean before you add it to your aquarium. If you don’t wash it properly, the fineness of the sand means that it can be suspended in the water for a long time, which raises the chances of it being sucked into your filter. The upside is that this fineness will help your plants take root quickly, but it may also result in some cloudiness in your water from time to time as the surface of the sand is disturbed by fish, snails or other bottom-dwelling creatures.

One good feature of Flourite Black Sand it that this plant-boosting substrate isn’t chemically treated or coated, so it can be safely used in your aquarium without changing the pH of the water.

Many aquarists are seeking to recreate the beauty of the natural world in miniature. If this sounds like you, then CaribSea Super Naturals Aquarium Sand could be just what you’re looking for.

This pH neutral sand is specially designed to ensure that all the particles are the same size, meaning that it can bring a beautiful uniformity and level quality to the base of your aquarium. This has the bonus feature of reducing the opportunities for waste to get caught in the surface.

One key feature of this sand is that it’s incredibly soft. This means is could be an excellent option if you have fish with sensitive barbels, such as corydoras or other bottom dwellers. They can snuffle around in it with complete confidence and you don’t need to worry that they might accidentally injure themselves.

This sand is completely safe for all aquarium systems, and there aren’t any paints or dyes used in its manufacture. It’s characterised by a beautiful golden-brown colour that results from a range of different brown, black, sand and taupe-coloured grains.

As this article shows, when it comes to sand in your aquarium, the choices are endless.

The key to choosing a sand is knowing your fish and understanding their needs. This will help you establish an aquarium that works well for them, which is more important than what works well for you! Unintentionally choosing the wrong sand could result in health problems or other issues for your fish, and you might find yourself having to empty your tank and start again.

We hope this article has helped you think through some of the key issues when it comes to choosing the right sand. Remember to consider:

After reviewing these five sand options, we’d choose Carib Sea Tahitian Moon Sand as the go-to option, especially for experienced aquarists who are looking to up the impact of their tank.

Why? Because it hits all the key issues you need to consider when looking for an aquarium sand, and it has these top characteristics to boot:

Just remember the caveats though – some fish may be sensitive, and you must clean it thoroughly before you add it. When you think it’s clean enough, clean it some more! And then clean it again! Check the pH before adding your fish, and you’ll be on your way to establishing a beautiful home aquarium.

What do you think? What’s your favorite sand for freshwater aqauriums? Add your thoughts in the comments below.

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