Aquarium Water for Plants: The Surprising Benefits

Using fish tank water to water and fertilize plants is a method that has gained popularity in recent years, as some gardeners swear by its effectiveness in promoting healthy plant growth. While it is possible that the nutrients and bacteria present in the water could provide benefits for plants, it's important to keep in mind that the water from an aquarium or fish tank could potentially contain chemicals or medications that could be harmful to plants.

In this blog post, we'll take a closer look at the potential benefits and risks of using fish tank water for plants, as well as some alternatives to consider.

Why use Fish tank water on plants?

Did you know that fish produce nitrogenous waste in the form of ammonia, which is then converted into nitrate by bacteria in the aquarium?

Nitrates are a form of nitrogen that plants can use for growth, and they are often present in fertilizers used for plants. In an aquarium, excess nitrates can build up over time and become harmful to the fish if they are not removed through regular water changes. However, when used in moderation, nitrates can be beneficial for plant growth.

There is some research and anecdotal evidence suggesting that using aquarium water to water and fertilize plants may provide certain benefits. For example, a study published in the journal Aquaculture found that lettuce plants grown in an aquaponics system using fish tank water had higher levels of nitrogen, phosphorus, and potassium compared to plants grown in soil with a commercial fertilizer.

Another study published in the journal Aquaculture, Nutrition, and Diet found that the use of fish tank water in an aquaponics system resulted in higher growth rates and nutrient uptake in basil plants compared to plants grown in soil.

In addition to these studies, many people swear by the effectiveness of this method, and they claim that their plants grow more vigorously and show fewer signs of nutrient deficiency when watered with aquarium water.

It's important to note that while fish waste can contribute to the nutrient needs of plants, it is not the only source of nutrients that plants need. Most plants require a range of nutrients, including macronutrients such as nitrogen, phosphorus, and potassium, as well as micronutrients like iron, zinc, and manganese.  

But Fish tank water is better than nothing! And it saves you from spending extra money on fertilizers. We are in a recession afterall!

What plants can benefit from Fish tank water?

Some plants that are known to do well with aquarium water include Pothos, peace lilies, and Chinese evergreens. These plants are known to be particularly responsive to the nutrients present in the water, and they may grow more vigorously when watered with aquarium water.

The truth is most species of houseplants will benefit from the use of aquarium water, particularly those that are sensitive to chlorine or other chemicals found in tap water.

How to Use Aquarium Water for Plants

If you're interested in using aquarium water for your plants, here are some steps to follow:

1. Collect the water from your aquarium or fish tank. It's important to use water that is as clean and healthy as possible, so be sure to clean your tank regularly and monitor the water quality to ensure it is suitable for your fish.
2. Let the water sit for at least 24 hours before using it on your plants. This will allow any chlorine or other chemicals to dissipate, making the water safer for your plants.
3. Dilute the aquarium water with a little bit of fresh water before using it on your plants. The water from an aquarium or fish tank can be quite concentrated with nutrients, and it's a good idea to dilute it to a more suitable strength for your plants. A 50/50 mix of aquarium water and fresh water is a good starting point, but you may need to adjust the ratio based on the specific needs of your plants.
4. Water your plants with the diluted aquarium water as needed, taking care not to overwater them. It's a good idea to monitor your plants closely and look for any signs of distress or nutrient deficiency. If you notice any negative effects on the plants, it may be best to adjust your watering routine or switch to a different method.
5. Dispose of any unused aquarium water in a responsible manner. It's important to avoid introducing excess nutrients or chemicals into the environment, so be sure to properly dispose of any unused water.

The Risks of Using Aquarium Water for Plants

Let's be honest, there are risks associated with everything in life.

While using aquarium water to water and fertilize plants may provide some benefits, you also have to consider potential risks. One of the main risks of using aquarium water for plants is the presence of chemicals or medications that may be harmful to plants.

Many aquariums and fish tanks are treated with chemicals to maintain the health of the fish and control the quality of the water. These chemicals may include medications to treat illnesses, as well as other substances like chlorine or water conditioners.

If the water from an aquarium or fish tank has been treated with these substances, it is possible that they could be harmful to plants if applied directly. It is generally recommended to avoid using water that has been treated with chemicals or medications on plants, as these substances could cause damage or illness in the plants.

To minimize the risks of using aquarium water for plants, it's a good idea to follow these precautions:

• Use clean, healthy water from a well-maintained aquarium or fish tank.
• Regularly clean the tank and monitor the water quality to ensure that it is suitable for your fish.
• Let the water sit for at least 24 hours before using it on your plants. This will allow any chemicals or medications to dissipate, making the water safer for your plants.
• Dilute the aquarium water with fresh water before using it on your plants. The water from an aquarium or fish tank can be quite concentrated with nutrients, especially ammonium and it's a good idea to dilute it to a more suitable strength for your plants.  In high concentrations, ammonia can be harmful to plants, as it can damage the leaves and cause browning or wilting.

For plant parents looking for an economical and natural way to provide additional nutrients to their plants without using commercial fertilizers, making your own fertilizer at home with banana peels is a great option.

Aquarium water + Banana peel fertilizers for plants

Plant parents can provide additional nutrients to their plants without spending money on commercial fertilizers by using household items like fish tank water and banana peels.

Fish tank water is a good source of nitrogen, which is an essential nutrient for plant growth, and it can be used to water and fertilize a wide range of plants. Banana peels are also a good source of nutrients, including potassium, phosphorus, and calcium, and they can be used as a natural fertilizer by chopping them up and burying them in the soil around the base of the plant.

Using a combination of these two methods can help to provide your plants with the nutrients they need to grow and thrive, while also saving money on commercial fertilizers. It's important to keep in mind, however, that these methods should be used in moderation, as excess nutrients can be harmful to plants.

Monitor your plants closely and look for any signs of distress or nutrient deficiency, and to adjust your fertilization routine as needed based on the specific needs of your plants.

Click here For a detailed guide on how to make fertilizers out of banana peels.

Conclusion

In conclusion, using aquarium water to water and fertilize plants can be a cost-effective and natural way to provide additional nutrients to your plants. There is some research and anecdotal evidence suggesting that this method may be effective in promoting healthy plant growth, and many plant enthusiasts have reported success with using aquarium water for their plants.

However, it's important to keep in mind that the effectiveness of using aquarium water for your plants will depend on the specific needs of the plants you are growing, as well as the quality of the water in your aquarium or fish tank. It may be necessary to use the aquarium water in combination with other fertilizers as needed to ensure that your plants are getting all of the nutrients they need to thrive.

If you are considering using aquarium water for your plants, it's important to be aware of the potential risks and to take appropriate precautions. This can include avoiding water that has been treated with chemicals or medications, letting the water sit for at least 24 hours before using it on your plants, and diluting the aquarium water with fresh water before applying it to your plants.

By following these precautions, you can help to minimize the risks of using aquarium water for your plants and ensure that they are getting the nutrients they need to grow and thrive.