Top 4 Best Substrate for Goldfish and Guide How to Choose The Right One

Every goldfish owner needs to make decisions before they jump into the fishkeeping hobby. Choosing the best substrate for goldfish is one of the decisions that will have a big impact on your goldfish’s health. There are different things that you have to take into consideration to make sure you create the perfect environment for your goldfish.

Choosing the best substrate for goldfish is an essential part of setting up an aquarium fish tank. It is not just for the aesthetic look of your tank, but it is also necessary for beneficial bacteria to cultivate and create good water chemistry.

Product Name




​GloFish Aquarium Gravel Fluorescent Colors​​​​


Carib Sea ACS05820 Super Natural Moonlight Sand


Marina Decorative Gravel


Royal Ram 2 Pounds Real Sand


Type of Substrate for Goldfish

There are different types of substrates on the market to choose from. All of them vary from different materials, sizes, colors, and chemical composition, which make the choosing process even more difficult.

Let’s jump into one of the best substrates for goldfish and find out which type is the best option.


This is probably the most popular choice of substrate for goldfish. It comes in a variety of different colors, sizes, and materials. However, gravel is considered to be a choking hazard for goldfish. Even though gravel is not necessary for goldfish, they would surely appreciate it.

Not only for the aesthetic looks of your aquarium but also for the gravel creates a place for beneficial bacteria to grow. By creating a layer of gravel on the bottom of the tank, you will also increase the level of biological filtration of your goldfish aquarium.

By nature, goldfish are feeding off the bottom of a goldfish tank, and since they have big mouths, you have to choose the right gravel size to avoid choking. Choosing pea-sized gravel might be the best size gravel for goldfish to prevent it from getting stuck in goldfish mouth. Also, it is excellent for anchoring plants into your aquarium.

– How to Clean Gravel Tank?

Cleaning a gravel tank is not that complicated, but you must be aware of a few things to keep the best water chemistry for your fish.

You can start by filling a bucket with dirty aquarium water until it is half-full. The remaining half should be filled up by clean tap water, just to prevent creating drastic water changes that might hurt the fish. After that, place the fish into the bucket and start the cleaning process of the tank.

Your next step is to remove your equipment and empty the tank. It is essential that you save some of the dirty gravel (two cups) just because cleaning the gravel with water will destroy most of the beneficial bacteria. Place the remaining gravel into a bucket and use a high-pressure hose to clean the gravel and stir vigorously until the gravel is cleaned.

Then clean the tank with water (avoid using soap or other chemicals) and place the mixture of dirty and clean gravel. Fill the tank with clean cold tap water and plug your electrical equipment. All you have left to do is to return your goldfish to a fresh and clean environment.


  • ​Easy to handle when cleaning
  • ​Suitable for anchoring plants and provides essential nutrients
  • ​Does not cloud the water
  • ​Good for beneficial bacteria growth


  • ​Dirt under the gravel cannot be adequately cleaned without emptying the tank
  • ​Gravel can cause barriers to the reflection of light into the aquarium
  • ​It is considered a choking hazard


Sand is also another option for the goldfish substrate. It is basically high-quality soft sand that is filtered and sieved to remove any particles and debris. It can be found in different colors if you want to add that ‘wow’ effect to your aquarium.

If you choose sand for the substrate of your fish tank, you should be aware of a few things. First of all, you should select a sand substrate designed explicitly for freshwater fish. Many sand options contain salt that might harm your fish.

Since it is very compact, it is perfect for anchoring plants and will prevent food from getting stuck at the bottom. Sand is an excellent substrate for creating a natural environment for the fish. However, it is worth mentioning that it might irritate the gills of goldfish, but there is no firm evidence to back this up.

– How to Clean Sand?

The best thing about sand is that there isn’t any waste falling through the sand and getting stuck at the bottom affecting the water mixture. This means that it is much easier to clean than gravel.

All you need to do is to filter out the surface of your sand with a siphon and clean the sand from solid particles before returning it into the tank. You can also remove the top layer of the sand with the hose every time you change the water.


  • ​The main benefit of the sand substrate is that it collects waste on top of the sand that can easily get removed
  • ​The natural environment for goldfish
  • ​Easy to clean up


  • Overtime, anoxic zones might develop in deeper pockets of the sand substrate. They can release toxins and affect water chemistry
  • It can get messy and when cleaning
  • Even though it provides excellent anchoring for plants, it does not allow plants to grow roots just because it is compact

​Bare bottom

The substrate is not necessary for goldfish, and you can have an empty bottom fish tank. Since they are relatively destructive fish compared to others and most of the time hungry, they might such up some gravel or sand particles causing health problems.

The most significant benefit of leaving a bare bottom fish tank is that it will be much easier to clean. Also, since there is no substrate, it is less possible to mess the watercolor, where using gravel or sand, you can see the water taking on the off-color or yellow tinge.

If you choose to go with no substrate, you will also free-up space for your goldfish to swim. However, bare bottom fish tanks are not that appealing to the eye. Even the waste from your goldfish will be visible, which will make your tank look unattractive.

The growth of algae will be much more prominent on the bare glass of the tank since there is no substrate. Also, if you want to grow plants in your aquarium, you must needs pots since there is nothing to put down roots into. Maybe the most significant drawback would be that it would affect your goldfish’s natural behavior.

More: Best Filters for Goldfish

– How to clean the bare bottom tank?

This is by far the easiest method for cleaning your fish tank. However, fish owners often forget that there is no need for frequent cleaning since there is no substrate. This means that beneficial bacteria need to be stored in the fish tank for maintaining a better environment.

The best way to clean a bare bottom tank is by using a vacuum, which should allow you to keep the water mixture right and remove unwanted particles.


  • ​Very easy to clean waste and uneaten food that might disrupt water chemistry over time
  • ​Improves water flow movement
  • ​Can save you money


  • ​Less appealing
  • ​Affects natural behavior of goldfish
  • ​Much easier to crack the bottom pane with other elements in the tank

Product Review

As we mentioned earlier, there are a lot of different substrates on the market to choose from. Finding the best substrate for goldfish is essential for maintaining a healthy environment for them.

Let’s jump into some of the best products.

1. GloFish Aquarium Gravel Fluorescent Colors – Best Gravel Substrate for Goldfish

If you are looking for bright-colored aquarium gravel designed to make your aquarium look amazing, this is the product to go for. This gravel comes in a low dust option, which will not affect the water when putting into the tank.

It is also easy to use, and you can add some decors to improve the fish tank even more. However, to achieve the best possible effect with this gravel, you must get full blue light and get that glowing effect. GloFish gravel does not have any sharp edges that might harm the fish.

They have a wide range of multicolor options, and the best thing is that it does not affect the pH of the water. This is the best gravel color aquarium gravel to achieve that incredible look on your fish tank.


  • ​Comes in vibrant colors for a significant effect
  • ​Safe for your goldfish
  • ​Not affect your water pH levels


  • ​Parts can chip off very easily
  • ​Sometimes you can get tiny particles that can fit in fish’s mouth
  • ​Food gets stuck under the gravel

2. Carib Sea ACS05820 Super Natural Moonlight Sand – Best sand substrate for goldfish

Carib Sea is the best sand substrate to go for since it makes your aquarium look colorful and yet provides all the necessary things for a healthy environment. It is a well-known substrate brand that is 100% natural substrate with no added dyes or chemical treatments that might harm your fish.

It also provides a great anchor for your plants and encourages plant growth for creating the ultimate natural environment. However, this sand has fine texture, and if you have a heavy water flow, it might make the water cloudy.

Its bright colors mimic the beach sands found in some exotic parts of the world, and it looks even better under blue light. Since this subtract is compact enough it does not allow waste or uneaten food to get beneath the surface.


  • ​Great for live plants
  • ​High-quality product and makes the tank look more appealing
  • ​Easy to clean


  • ​Might make the water cloudy when putting in

3. Marina Decorative Gravel – Best Visual Effect

If you are looking for the best substrate for goldfish that will make your aquarium look amazing, Marina decorative gravel is the way to go. They provide a wide range of colors such as black, orange, purple, neon, yellow and etc. that are suitable for everyone’s needs. They also pop out when you use blue light.

This is the best way to add some personality to your tank and make your goldfish stand out. This gravel is coated in epoxy, so you would not have to worry about affecting your water chemistry. Also, it is the best size gravel for goldfish and does not have any sharp edges that can harm your fish.

It is also great for creating the perfect place for beneficial bacteria to grow, which are necessary for maintaining a healthy environment for your goldfish.


  • ​Best size and round edges
  • ​Many different colors available
  • ​Great for beneficial bacteria growth


  • Not suitable for larger tanks

4. Royal Ram 2 Pounds Real Sand – Best Natural Sand

Royal Ram 2 Pounds is an excellent sand substrate for your goldfish. It comes in a variety of colors such as marble white, maroon red, green, etc. which makes every tank look amazing. Since it is a natural product it does not contain any chemicals or dyes that will affect your water pH levels.

It is made from natural rock products that are grounded into small pieces. It also provides a great way to anchor down plants and beneficial bacteria growth. Royal Ram will give you that natural feel on your aquarium and yet still look fantastic with different colors.


  • ​Does not affect water chemistry
  • ​Vibrant colors
  • ​All-natural


  • ​Not suitable for root growing

What is the Best Substrate For Goldfish?

Considering that there are a lot of options to choose from, sometimes it might be challenging to select the best substrate for your goldfish. To answer this question, you need to ask yourself how the chosen substrate can affect your fish’s health and overall aquarium experience you are looking for.

All three options are suitable for your goldfish, but you need to choose the one that satisfies your expectations. We went through the pros and cons of each product, and deciding the best substrate for goldfish is entirely up to you.

The bottom line is that you must keep your fish healthy, and choosing the right substrate or go for bare bottom tank have different requirements and responsibilities. You must select the one you are most comfortable with.


The fishkeeping hobby is trendy, and there are a lot of requirements you need to be aware of before you jump into it. Also, there are a lot of low-quality substrates that you need to avoid to avoid unnecessary health problems for your goldfish.

Using this guide, you have the necessary information to make the right decision and create the ultimate aquarium experience for both you and your goldfish.


  • William Rieder

    Hi, my name is William Rieder and I'm a pet and animal blogger. I love reviewing all things pet related, from dogs to cats to horses! I also write about other topics such as personal finance and relationships. I enjoy helping people find the perfect pet for their lifestyle and am always interested in hearing what they have to say about their pets.

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