How to Add Substrate to an Established Aquarium

The substrate in an established aquarium is the material that sits at the bottom of your tank and provides a surface for plants, fish waste, and other materials. The most common substances used as substrates are gravel, sand, and crushed coral.

How to Add Substrate to an Established Aquarium

Choosing which one to use depends on several factors, including what you want it to look like, how much money you want to spend, whether or not you have existing plants or fish in your tank, and what type of aquarium filter system you’re using. Read on to find out more about how to add substrate to an established aquarium so that you can make an informed decision about which one will work best for your home aquarium!

What Type of Substrate is Best?

Gravel is the most common and least expensive type of substrate used in aquariums, and sand is a popular choice with some aquarists because it can be used to create a more naturalistic-looking tank. However, gravel does not provide any hiding places for your fish and helps prevent injuries because it is soft and won’t cause scrapes the way some gravels do.

Several types of sand are commonly used in aquariums, including white silica sand, play sand, pool filter sand, and others. White silica sand is often sold specifically as a substrate, or sand can be difficult to clean. Both are fine choices on their own. The decision between these two substrates is typically made based on aesthetics alone.

Gravel Is Least Expensive Type of Substrate

Reason to Add Substrate to an Established Aquarium

Adding substrate to an established aquarium is not necessary unless you’re creating a new look in your tank or you want to add plants. If you have gravel, sand, crushed coral, or another material at the bottom of your tank that doesn’t have any plants or fish waste on top of it, then that layer will provide all of the benefits of having a substrate in your aquarium.

Methods on How to Add Substrate to an Established Aquarium

Methods 1:

Add old substrate to the new substrate – this works best if you create an entirely new look in your aquarium. Once you have removed all of the water from the tank, pour the new substrate on top of your old one and mix it with your hands to make it easier to bury any plants or decorations you wish to add.

This method works great if you want to use a different type of substrate in your tank, but it does require removal/replacement of the old substrate and maybe more work than necessary, depending on the size of your tank.

Adding Old Substrate to the New Substrate

Method 2 :

Add new substrate on top of existing substrate – this is not recommended for larger tanks because adding too much substrate on top of the old stuff will raise your waterline. If you want to add a new layer of the substrate without raising your water level too much, it’s recommended that you use the same type of substrate.

Mixing different substrates can result in an uneven distribution of materials and hurt plant growth, which defeats the purpose of adding substrate. If you decide to go this route, adding the new substrate in a couple of layers is a good idea because it may raise your waterline a little bit.

How Often Should You Clean Substrate?

You should clean your substrate as often as needed, which will vary from tank to tank depending on what type of substrate you have and what type of filter system you’re using. The frequency typically depends on how many fish and plants you have in your aquarium, the size of your tank, and whether or not you feed your fish regularly.

Tips and Warnings


When choosing a substrate, you should consider what type of look you want the substrate to have in your tank. Sand can be used to create a more naturalistic-looking tank, but gravel does not provide any hiding places for fish, and plant roots grow better when they’re planted in the sand.

Adding too much substrate will raise your water level and make it harder to maintain the water parameters in your aquarium.


  • Avoid mixing different materials in your substrate, this will make it harder to plant, and the plants’ roots may not be able to grow through the new substrate.
  • If you decide to add an entirely new look to your tank, remember that you’ll need more than just substrate when planting because you also need nutrients for healthy plant growth. You should also use a substrate conditioner that will provide nutrients to the plants.
  • If you’re adding substrate to an established tank, be sure to monitor your water quality closely because changing the substrate can affect it. -Once you have added new substrate to your tank, wait for two weeks before adding any fish so that there isn’t a massive ammonia spike due to shifting bacteria colonies.
  • Avoid changing the substrate in a fish tank as much as possible because doing so will stress out your fish and can even kill them. If you have to replace any substrate, it’s best to remove all of the water from the tank, clean or replace the old substrate, then add the new substrate and fill the tank with water.
  • If you have shrimp in your tank, never use Clorox because the process of decomposing it will kill them off.
  • Substrate should not be bare or exposed when adding to an established tank because the bacteria that is needed for a healthy environment and good filtration won’t be present and can harm your fish.
Considering the Size of  Aquarium

You Can Check It Out to: Prepare Large Driftwood for Aquarium


You will want to consider the size of your aquarium, how many fish you have, and what type of plants or substrate would be best for the environment. For example, suppose you are new to keeping an aquarium. In that case, it is important that you invest in not only the tank itself but also all of the necessary items needed, such as a filter or heater, depending on where you live. Once these things are taken care of, think about which types of plants might work best with your new setup and whether they need any special lighting requirements. This article has provided some great tips on how to add substrate to an established aquarium, so don’t hesitate to reach out if there is anything else we can help with! Thank you for reading our article.

you may read it also – How to Plant Carpet Seeds in an Established Aquarium .

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