Best Fish Tank Substrates for 2020

A great mix of different colours, gravel sizes and silicate types for your tank to really have that natural sea feel and keep all of your fish happy.

It looks decorative but also gives your fish somewhere perfect to explore and play in. the stones will need rinsing thoroughly before they are placed in your tank, but the colourfast resin coating will ensure that the colour doesn’t start leaking into your water over time. This also means it won’t affect the pH levels or cloudiness.

If you have plants, it makes a perfect medium due to the smaller size, allowing good bacteria to grow and the plant to remain in place. You can purchase it in a 2kg or 8kg bag, so you get the perfect amount for your tank size.

Hugely colourful gravel can really help when your fish are also hugely colourful, such as a school of Tetras.

With the contrast of the green plants and decorations, it will make a striking display. This Marina collection is dust-free, non-toxic and epoxy-coated, making it perfect for use in an aquarium. It is the ideal size to provide a perfect breeding ground for bacteria colonisation, to maintain clear water.

As with all gravel, wash before you use to remove any dust. Users have said that the colour still remains as vivid one or two years on, which is great news for longevity.

Sand is great for burrowing fish or those bottom-feeders, or indeed as a base under your gravel to keep plants and other decorations secure.

Available in four colour varieties, you can pick the one which will make your tank look just the part. It is great to use as a plater medium due to the fine size, and it all looks really dazzling under lighting.

Sand needs turning to aerate it every so often, but this one is easy to clean with a vacuum held far enough away as any dirt just sits on the top layer. It is great for axolotls or bottom-dwelling fish as it is soft and easy to walk on or burrow into.

Pebbles are best used as decorative elements or to secure your ornaments and plants if you have fish who like to pull and play with them, moving or bringing them out.

They are all large stones, so won’t easily be disturbed by small fish. They’re ordinary smooth stones, so will need taking out and cleaning occasionally, but once they have been washed they are safe for use in your tank.

How many you get in a bag differs, unfortunately, but in general, it seems to be between 8 and 12 large stones to make up the overall weight which should be enough for decorative issues. If you’re thinking that they’re expensive so you should nip to the beach and pick some up instead, think again – these ones are the safest and least toxic for your tank water.

These are also ideal for using in a dedicated small BiOrb with just one or two fish in.

If you have a planted tank and living plants which require just as much care and attention as the actual fish, getting the best layer of any substrate to help them stay alive is vital.

This volcanic soil, which looks like little balls, stimulates strong plant growth, making it better than using sand or stone. It helps keep the tank at a neutral to slightly acidic pH level, so is best for tanks where the fish require this level.

The plant roots easily branch into the substrate, spreading as they grow and becoming more secure for any fish who are a bit mischievous and like to pull at them. If you have shrimp it can also be great, as they can hide in the substrate until they are old enough to come out and not be bullied or threatened.

It’s not good for any fish who like to move the tank bedding around, nor African and Central American cichlid species, goldfish or koi. It also can’t be used in saltwater, and shouldn’t really be used with other gravel mixes.

One of the best for overall choice, in terms of both colour and bag sizes, so you can find the perfect match for your tank.

It is not toxic and remains dust-free once initially rinsed. Each piece is between 3mm – 8mm, so it is good for little fish who like to burrow and hide as well as larger ones who may want to move things around.

Great quality, don’t be put off by the fact it can also be used as a plant pot topper. If you have some leftover, at least this means it will still come in use!

A choice of ten neutral finishes and colours means you can pick the exact look you’re after for your fish tank.

It is suitable for cold water, tropical and saltwater tanks, and the small size means there is a higher surface area which makes it ideal for anaerobic activity and good bacteria production. It also makes for the perfect planting medium.

Suitable for bottom feeders and barbed fish as the edges aren’t too harsh and sharp. As they’re made from silica aggregates, they’re pretty inert and they’re covered in colourfast resin to ensure there is no pollution in the tank.

Perfect for decoration as well as using as a planting medium, this sand is nice and fine to act as a gravel base or on its own.

The price is good for how much you get, as there is a good chance you will only need one or two bags for the size of your tank.

It takes quite a bit of cleaning as it is so fine, and needs a good few hours to settle as well. Make sure you have a filter which can keep the water clear. It also goes darker when wet which is understandable but you need to think about it before buying.

Crushed coral won’t be for every tank, as the 100% aragonite mix is purely for tanks which need to maintain a good pH level in saltwater tanks.

Even just the smallest bit will alter the pH level drastically, so it really does the job. This large bag could, therefore, last a lifetime. It can recreate natural reef environments, and will even look very pretty thanks to the little seashells and natural products mixed in.

The price is quite high for a bag of its size, but it is a very speciality product so it will be worth paying that bit more for something which is quality. The aragonite gives you 25x as much buffering power compared to other coral forms, which again is worth paying for if you really care about your fish.

A huge 10L tub if you have a lot of tank to fill, but it is also available in some smaller tubs if needed. In kilograms, this works out as double so is 20kg.

It is bright, natural and decorative to really add a touch of class to your display. Non-toxic, it won’t damage the water pH levels or make it cloudy. Once it has had its initial clean, it will remain dust-free. 

Each stone has a diameter between 3 and 8mm, making it safe for use with pretty much all fish breeds. It’s 100% natural, with no chemicals which can harm your fish, and it can also be used in outdoor ponds.