How to Turn a Fish Tank Into a Garden?


If you’re a gardener, then you know that there’s always something new to learn. And if you’re looking for ways to expand your garden, then you might want to consider turning your fish tank into a garden! This can be a great way to add some extra plants to your collection, and it’s a project that anyone can do with a little bit of effort. In this guide, we’ll answer some common questions about how to turn a fish tank into a garden, and we’ll provide some useful tips that will help make the process go smoothly. So read on for information that will help you get started on this fun gardening project!

Why Turning an Old Aquarium into a Garden is a Great Project Idea

If you have an old aquarium that you no longer use, turning it into a garden can be a great way to upcycle it. Not only will you be able to reuse the aquarium, but you can also create a unique and beautiful space in your home.

Finds a new purpose to your old tank

Aquariums are often seen as a one-time purchase. Once you set them up, they become part of your furniture. But what happens when you no longer want or need an aquarium? Most people simply get rid of them, but there are other options. One option is to turn your old aquarium into a garden.

Finds a new purpose to your old tank

This is a great way to give your old aquarium a new purpose and extend its life. Not only that, but it can also be a fun and unique project that will add character to your home.

It saves you money

Another reason why turning an old aquarium into a garden is a great idea is because it can save you money. If you were to buy all the necessary supplies to set up a new home garden, it would likely cost you more than simply repurposing your old aquarium.

Customization options for your new garden

When you turn an aquarium into a garden, you have complete control over the design. You can choose what plants to grow, how to arrange them, and what type of soil to use. This gives you the opportunity to create a space that is truly unique and personal.

If you are not sure where to start, there are plenty of resources available online and in gardening stores. You can also find used aquariums for sale if you do not have one already.

It can serve as a portable garden

One of the benefits of turning your aquarium into a garden is that it can serve as a portable garden. If you have a small space, such as an apartment, you can move the aquarium around to different areas of your home to change up the look.


One of the best things about turning a fish tank into a garden is that it can be a real showpiece in your home. A well-designed and planted aquarium can be a real conversation starter and add some personality to your living space.

For example, you can create an aquarium garden specifically for tropical plants. This can add a touch of the tropics to your home and give it a unique look. [1]
If you are someone who loves plants and enjoys being surrounded by them, then having a garden inside your home can be really beneficial for your mental health. Studies have shown that being around plants can help reduce stress levels and improve moods. So, if you are looking for a way to turn your old fish tank into something that will benefit your health, then creating a garden is definitely the way to go.

Types of Fish Tank Gardens

There are two types of fish tank gardens: those with an open lid and those with a closed lid. Each has its own set of benefits and drawbacks that you should consider before making your decision.

Open gardens

An open garden is one where the lid of the fish tank is removed. This type of garden is great for a number of reasons. First, it allows more light to reach the plants, which is essential for photosynthesis. Second, it provides better air circulation, which is important for the health of both the plants and the fish. Third, an open garden is easier to maintain because you don’t have to worry about water evaporation.

Open gardens

However, there are also some drawbacks to having an open garden. First, without a lid, your fish tank is more susceptible to dust and debris from outside sources. Second, if you have small children or pets, they may be able to access the tank and disturb the delicate ecosystem you’ve created.

Closed gardens

Closed gardens are fish tank gardens that are closed with a lid. These gardens are better called ‘terrariums’ since they provide a more controlled environment for your tropical plants.

The biggest advantage of closed gardens is that it helps to keep the humidity levels high, which is beneficial for most plants.
However, one drawback is that it can be difficult to access the plants if you need to prune or water them.

This type of fish tank garden is harder to maintain because the levels of humidity are harder to control. Additionally, the type of environment created within such a garden is unsuitable for a large amount of plant species.

In order to decide which type of fish tank garden is best for you, it’s important to consider the benefits and drawbacks of each. Think about what type of plants you want to grow and what kind of environment they need in order to thrive. Also, take into account your own lifestyle and whether or not you have the time and patience to maintain a closed garden. [2],[3],[4]

Can All Fish Tanks be Repurposed as Mini-Gardens?

The answer to this question is yes and no. Any fish tank can be turned into a garden, but not all tanks are created equal. The size, shape, and material of your aquarium will determine how successful your garden will be.

For example, if you have a small tank made of glass, it might be difficult to fill it with enough plants to create a thriving mini-ecosystem. However, if you have a larger tank made of either glass acrylic, then you will have more success in growing a variety of plants.

Fish Tank Materials that Work Best for Plant Growth

This leads us to the second factor, the material of the glass tank.

When it comes to materials, acrylic is one of the best options for plant growth. Acrylic is a clear plastic that is often used in aquariums. It is durable and resists damage, which is important if you want to keep your plants looking their best, although when it comes to scratch resistance, it won’t fare as well. Additionally, it is easier to drill holes into acrylic, which will be necessary for planting.

Glass is another popular material for fish tanks. However, glass can be difficult to drill and does not resist breaks as well as acrylic. That aside, glass does provide a clear view of your plants, which some people prefer. [3],[5]

Consider the Size of Your Tank

The size of your tank is one of the most important factors to consider when repurposing it as a garden. A small tank might not be able to support the growth of many plants, and a large tank might be too difficult to maintain.

Consider the Size of Your Tank

Ideally, you want to find a happy medium between the two.

A good rule of thumb is to choose a tank that is at least 30 gallons.
This will give you enough space to grow a variety of plants without being too difficult to care for.

Additionally, if you are planning on keeping reptiles in your aquarium-turned-garden, then you will need to make sure that the tank is large enough to accommodate them. [3]

Consider the Plants Growing Requirements

Before you start planting, it is important to take into account the requirements of the plants you want to grow. Make sure that they will have enough space to grow and that they won’t overcrowd the fish tank. Next, you will need to choose plants that are appropriate for the amount of light that the aquarium receives, as well as the humidity within the tank. If the aquarium is in a location that doesn’t receive much natural light, you might need to supplement with artificial lighting.

Another important factor is the soil type. Some plants prefer sandy soil while others do better in clay soil. There are also plants that can grow in both types of soil. It is best to choose a plant that is suitable for the type of soil you have in your fish tank.

What Plants Can Grow in a Fish Tank Garden?

There are a wide variety of plants that can be grown in a fish tank garden. Some of the most popular plants include:

  • Lettuce
  • Spinach
  • Cabbage
  • Kale
  • Chard
  • Herbs (such as basil, oregano, and mint)

Of course the list doesn’t end there. While it’s preferable to grow plants that prefer medium-low light conditions and higher humidity, as long as you will be providing the plants with the proper care, almost any plant can be grown in a fish tank garden.

Even garden veggies like tomatoes can be grown in a fish tank garden, though you will need to provide them with a support system (such as a tomato cage) and make sure they get enough light. As long as they have enough space to grow obviously!

If you are looking for more ideas, there are many online resources that can help you choose the right plants for your fish tank garden. Although due to the limited space, it’s not recommended to grow large plants in a fish tank garden, so keep this fact in mind. [2]

Gather the Supplies You Will Need

Once you have chosen the plants you want to grow, it is time to gather the supplies you will need. Here’s an overview of what you will need for this project, besides the fish tank!


You will need gravel to line the bottom of your fish tank. This will help with drainage and prevent waterlogging of your plants’ roots. You can either buy gravel from a gardening store or collect it outdoors. If you choose to collect gravel from outdoors, make sure to wash it thoroughly before using it in your fish tank since it might contain bacteria or other harmful substances.

Activated charcoal

Another important component of your fish tank garden is activated charcoal. This substance helps to keep the water in your tank clean and free of toxins. You can buy activated charcoal at a pet store or online.

Small seedlings or seeds

Of course, you will need plants for your garden! You can either start with small seedlings or grow your plants from seeds. If you choose to grow your plants from seeds, make sure to get a soil mix that is specifically designed for growing plants in fish tanks.

Spray bottle

A spray bottle is a helpful tool for watering your plants. Make sure to get one that has a fine mist setting so you don’t accidentally damage your plants.

Potting mix

Of course we couldn’t forget to bring up yet another crucial element of any garden. Be it a pot or a fish tank, you will need potting mix to grow your plants in. Potting mix is a type of soil that is well-suited for growing plants in containers. You can buy potting mix at a gardening store or you can make one yourself.


You will need a mild detergent to clean the fish tank before you start planting. Make sure the detergent is compatible with the material of your tank.

Decorations (optional)

If you want, you can add some decorations to your fish tank garden. This is completely optional and up to you! Some people like to add rocks or statues to their gardens, while others prefer to keep it simple.

Aquarium rocks or stones can be used as decoration in your garden and also serve a practical purpose. They can help to anchor plants in place and act as a support for climbing vines.

Decorations (optional)

No matter what you choose,remember that the most important thing is that your plants have enough space to grow.

Repurposing Your Fish Tank as a Garden

Now that you have gathered all of the supplies you need, it is time to start repurposing your fish tank as a garden!

Clean the tank with hot water

The first step is to clean the fish tank. You will need to wash the insides with hot water and a mild soap. Be sure to rinse the tank well afterwards. You may also need to remove any algae or other growths from the sides of the tank. This can be done by scrubbing the inside of the tank with a sponge or brush. [1],[2],[4],[6]

Use detergent if needed

If the tank is very dirty, you may need to use a detergent. To use it safely, mix the detergent with hot water and apply it to the inside of the tank. You may need to repeat this process a few times to get the tank completely clean.

Get rid of all chemicals

After the tank is clean,  you will need to remove all chemicals left after using a detergent on it. To do this, you can rinse the tank with a solution of water and vinegar. [1],[2],[6]

Check for cracks

Once the tank is clean, you will need to check for leaks. To do this, fill the tank with water and let it sit for a few hours. If there are any leaks, the water will escape from the tank. You can then repair the leaks with a sealant.

You should now have a clean fish tank that is ready to be turned into a garden! In the next section, we will discuss how to prepare the soil for planting.

Add gravel at the bottom

The next step is to add gravel at the bottom of the fish tank. This will aid with drainage and keep the roots of your plants healthy. You can find gravel at any gardening store or online. You will need to decide how deep you want the layer of gravel to be, usually it will depend on the depth of your tank. A good rule of thumb is to make it about as deep as the roots of your plants.

Drainage is one of the most important things to consider when starting an indoor garden. Without proper drainage, your plants will quickly become waterlogged and could die. Most fish tanks have a hole in the bottom that can be used for drainage, but you’ll still need to add a layer of rocks or gravel to help keep the water from draining too quickly.

Add the activated charcoal on top

After the gravel is in place, you will need to add a ½ inch layer of activated charcoal. This will help to keep the environment clean and free of toxins.

Add the activated charcoal on top

Activated charcoal is not only a great way to get rid of the bacteria, but also improves the drainage even further and ensures your soil will stay fresh for longer.

Add sphagnum moss if you need

The next step is to add sphagnum moss if you need to. This will help to keep the roots of your plants moist. You can find this moss at any gardening store or online.

Sphagnum moss is a plant that is commonly used as a soil-less media for growing plants. It is also known as peat moss. Sphagnum moss has many benefits for gardeners. Some of these benefits include:

  • It holds moisture very well, which is beneficial for plants that require high levels of humidity.
  • It has a neutral pH, which means it will not alter the pH of your soil.
  • It is an excellent source of organic matter.
  • It is lightweight and easy to transport.
  • Adds acidity

Keep in mind that it’s recommended to add sphagnum moss only if you are planning on planting tropical plants or plants that require high levels of humidity.

Sphagnum moss is not necessary, but it does help to keep the roots of your plants reasonably moist. If you live in a dry climate, or if your fish tank doesn’t get much sunlight, adding a layer of Sphagnum moss can be beneficial. Moss is often used in terrariums and vivariums because it helps retain moisture and prevents evaporation.

However, because sphagnum moss is an organic material, it will break down over time. You will need to replace it every few years. [6]

Adding gravel and activated charcoal to your fish tank is an important step in preparing it for planting. In the next section, we will discuss how to choose the right plants for your garden.

Add quality soil on top

After the gravel and activated charcoal are in place, you will need to add quality soil on top. This will be the home of your plants.

It is important to choose the right type of soil for your plants. As we mentioned before, regular potting soil will be ideal for your fish tank garden. You will need to find a potting mix that is specifically designed for indoor gardens. This type of soil will provide the necessary nutrients for your plants to thrive. Be sure to choose a soil that is well-draining and free of toxins. This will help to ensure that your plants don’t become waterlogged.

Add quality soil on top

Once you have added the soil, you are ready to start planting!

Plan the plant arrangements

The next step is to plan the plant arrangements. You will need to consider the size and shape of your fish tank when planning the layout. Be sure to leave enough space between each plant so that they have room to grow.

When choosing plants for your garden, it is important to consider their root system. Some plants have very aggressive roots that can quickly take over a small space. If you are unsure about a particular plant, ask a gardening expert or do some research online. [1]

Once you have chosen the plants for your garden, it is time to finally place them in their new home!

Plant the seeds or seedlings

The next step is to plant the seeds or seedlings. If you are using seedlings, simply plant them in the potting mix and add them to the tank. If you are growing your plants from seeds, follow the instructions on the packet before planting them in the potting mix. Be sure to plant them at the correct depth of the holes and spacing. Once your plants are in place, water them lightly with a spray bottle. [1],[2],[4],[6]

Place decorations in the tank

After your plants are in place, you can add some decorations to the tank. This is completely up to you and will depend on the look you are going for.

You can find these decorations at your local gardening store or online.

It’s important to clean them before adding them to the tank, so that they don’t introduce any harmful chemicals or bacteria into the environment.

Proper Care After Your Fish Tank Garden Is Set Up

After your fish tank garden is all set up, it is important to give it the proper care. This includes ensuring that the plants are getting enough light and water. As well as some extra care steps.

Water the plants regularly

One of the most important things you can do for your fish tank garden is to water the plants regularly. This will ensure that they are getting the moisture they need to stay healthy.

Water the plants regularly

The best way to do this is by using a spray bottle to mist the plants with water. You can also use a watering can, but be careful not to overwater the plants. Consider the watering requirements of each plant in your garden and water accordingly. Keep the spray bottle near the tank for easy and fast access.

Keep the light in mind

Another important factor in caring for your fish tank garden is the light. Most plants need at least six hours of sunlight a day to grow properly. For this reason, make sure to place the fish tank in a location where it will get plenty of light.

You can also grow lights for certain plant species to supplement the natural light if needed. Just be sure to follow the manufacturer’s instructions when using grow lights.

Fertilize the garden if needed

In order to keep your plants healthy, it is important to fertilize them on a regular basis. You can use either liquid or granular fertilizer for this purpose. Be sure to follow the instructions on the fertilizer package. Overfertilizing can damage the plants, so it is important to be cautious.

Fertilizing is not always necessary, but if you notice that the plants are not growing as well as they should be, then it may be time to fertilize.

Keep the tank clean

It is important to keep the fish tank clean, in order to maintain a healthy environment for the plants and fish. This means that you will need to carefully clean the walls of your tank garden when they get dirty.

You can use a sponge or soft cloth to clean the walls of your tank. Avoid using any harsh chemicals, as they can damage the plants. [1],[2]

Look out for the pests and diseases

Pests and diseases can be a problem in any garden, including fish tanks. Always keep an eye out for any signs of pests or diseases. If you notice anything unusual, take measures as soon as you can.

Most common pests you can encounter in fish tank gardens are mealworms and ants. As for diseases, root rot is a common problem.

There are many ways to combat pests and diseases in your fish tank garden. However, using toxic pesticides indoors can harm your health, so it’s recommended to use non-toxic methods. [1],[8]

How to Create Your Own Potting Soil

When you’re used to gardening in the ground, it can be confusing to try and figure out what kind of soil to use for your new fish tank garden. The most important thing to remember is that potting soil is different from the garden soil you’re probably used to. Garden soil is heavier and will compact in the smaller space of a fish tank, which can lead to problems with drainage. Potting soil is lighter and airier, which helps prevent compaction and allows your plants’ roots to breathe.

So from this we can conclude that one of the most important things you need for a fish tank garden is potting soil. Potting soil is a type of soil that is specifically designed for plants in containers.

However, it is also possible to make your own potting soil at home. If you want to create your own potting soil, you will need:

  • 5 quarts of vermiculite or perlite
  • 10 quarts of coconut coir
  • 5 quarts of peat moss
  • Some fine sand
  • 5 quarts of compost or manure
  • Pelleting fertilizer

To make your own potting mix, simply mix together required parts of each ingredient. Once you have mixed everything together, add water until the potting mix is moist but not soggy.

Now you have your own potting mix to add to your fish tank garden! [7]

How to Properly Arrange the Plants in Your Tank

One of the most important things to consider when setting up your fish tank garden is how you will arrange the plants. The arrangement of the plants can have a big impact on the overall look of your garden, as well as the health of the plants.

How to Properly Arrange the Plants in Your Tank

It’s important to not overcrowd the plants in your tank. This can lead to problems with the roots of the plants, as some of them may simply not grow. You should also consider the size of the plants when you are arranging them. Some plants will grow to be very large, while others will stay small.

You should also give each plant enough space to spread its roots. If the roots of a plant are crowded, it can cause problems with the plant’s growth.

If you are planning on creating a fish tank garden purely for aesthetics, you should also consider the color of the plants when you are arranging them.
You can create a very striking effect by contrasting the colors of the plants. [9]


Can you grow tomatoes in a fish tank?

Yes, you can grow tomatoes in a fish tank. However, you will need to provide them with plenty of light and water. You may also need to fertilize the soil to provide the plant with some nutrients. However since tomatoes are quite large plants, you will need a very large fish tank to grow them.

Can you grow vegetables in a fish tank?

Yes, you can grow vegetables in a fish tank. However, it is important to note that not all vegetables are suitable for growing in a fish tank. For example, root vegetables such as carrots and potatoes require a lot of space to grow properly and may not do well in a fish tank. Instead, focus on growing leafy greens and other plants that don’t require a lot of space.

How do you repurpose a fish tank?

One of the options you can repurpose your fish tank as is indoor garden. You can use it to grow your own herbs, leafy greens, or flowers. If you have a fish tank that is no longer being used, here are some useful tips on how to turn it into a garden.

Can all vegetables be grown in a fish tank?

Unfortunately, not all vegetables can be grown in a fish tank. Some vegetables require more space than a fish tank can provide. However, there are still plenty of vegetables that can be successfully grown in a fish tank garden. Some of the most popular choices include lettuce, spinach, tomatoes, peas, and beans.

Useful Video: Turn your old garden corner into a great relaxing place with this simple waterfall fish tank


If you’re looking for a fun and easy project that can add some life (literally) to your home, why not try turning your fish tank into a garden? It’s entirely possible, and doesn’t require much effort or know-how. All you need is a clean tank, some gravel and activated charcoal to create a drainage system, potting soil, and plants of your choice. So get creative and have fun with it!