Do Aquaponics Systems Need A Water Filter?

Aquaponics is a symbiotic relationship between fish and plants. And while it is naturally self-sustainable and a filter on its own, not all the waste is filtered. This is why many aquaponics growers use additional water filters to enhance the performance of their system. Which leads beginners in aquaponics to wonder, do aquaponics systems need a water filter? 

Water filters are not required in aquaponics systems, but adding a good filtration system can help maintain good water quality and improve your fish and plants health. This article will discuss the filtration in aquaponics systems and how they can help your system.

What is Water Filter in Aquaponics?

The water filter in aquaponics is a tool that helps filter excess water, especially solid waste, such as decaying organic matter and excess food from your tank. As the fish and other aquatic creatures continuously produce wastes in the tank, toxins may build up‌.

If these toxins are not removed from the tank, it may cause the accumulation of ammonia, which could lead to ammonia poisoning. 


DIY Water Filter in Aquaponics

Does Aquaponics Need a Water Filter?

Excess waste, such as solid waste‌ in the tank, can become a challenge as these excess solids are pushed into the grow bed and may clog your water pump and grow beds. Here are the effects of excess solid waste: 

  • Too much solid waste can affect your system's water quality, which may cause fish and plant death.

  • A densely stocked fish tank could produce too much fish waste, which can cause high ammonia levels.

  • This excess solid waste will remain in the water and may clog your pipes, grow beds, and water pump.

  • The excess solid waste will reduce the surface area for the bacteria to live.

  • Solid waste can create a sludge at the bottom of the grow beds, creating gasses and aerobic zones for the bacteria. 

  • The excess solid waste can get caught in the plant roots, blocking the water flow and causing brown roots. 

Thus installing aquaponics filtration systems is necessary so your system can benefit from the clean nutrient-filled water. 

The Benefits of Using Water Filter in Aquaponics

Ammonia is toxic to fish and other aquatic animals, even at low levels. Fish expel ammonia through their urine, gills, and waste. Since the fish tank is densely stocked, this could lead to higher ammonia levels.

This is one important reason a filtration system is recommended in aquaponics systems. While aquaponics growers have different opinions on the importance of filters, here are some benefits of using a filter in your aquaponics system. 

  • Healthy Fish and Plant Growth

Unfiltered water may contain high levels of pH and ammonia, which could affect the growth of your fish and plants. Filtering the water in your aquaponics system will lower ammonia, pH levels, and other solid toxins that could affect your fish and plants. Excellent water filtering system can help in maintaining good water quality.

  • Optimal Environment 

Clean and healthy water helps maintain the optimal environment for your system. By removing excess solid waste, chemical contaminants, and other unnecessary substances, your fish could avoid diseases caused by the polluted water. Your system will thrive and become more successful because water filters help ensure the healthy growth of plants and fish.

  • Sustainability

Filtering the water in your aquaponics system will minimize the overall water usage and strengthen the objective of having a sustainable system


Raft Water Filter in Aquaponics

Types of Filtration for Aquaponics

The types of filters used in aquaponics are:

1. Mechanical Filters

Mechanical filtration is the removal of large solid waste, such as uneaten fish food and feces, through a series of filter media. Several types of filter media, such as a sponge, screen, or activated carbon, are used to catch solid waste to keep the water clean. Some aquaponics growers use DIY filter media to save money, while some use pre-made filters they can purchase.

DIY or pre-made, the effectiveness of your mechanical filter will depend on a proper understanding of how mechanical filtration works, correct setup, and regular maintenance. Filter media, like activated carbon, catches contaminants such as lead, chloramine, and water‌ pollutants.

Using your activated carbon filter system to capture water pollutants before reaching your fish tanks is essential. If you are using water from private wells, you need to test the water for contaminants, but if you have a reliable water source, you don’t need to use activated carbon. 

Some most popular active filters used for aquaponics systems are:

  • Radial Flow

The radial flow filter uses a 50 gallons barrel. A pipe is connected from the tank into the middle of the barrel and a pipe that comes out at the top of the barrel facing 90 degrees. Where the solid waste flows down into the barrel through the pipe and settles at the bottom of the barrel, the clean nutrient-rich water is filtered through the 90 degrees upper pipe and flows into the grow bed.

  • Swirl Filter

A swirl filter is mostly used for grow beds. It uses a large barrel-shaped container where there is a basket that filters solid waste outside. Swirl filters work by collecting the water from the tank, and as the barrel fills up, a swirl effect will be activated, slowing down the rising water level. This helps the solid waste settle at the base of the barrel. The nutrient-rich water then moves from the top of the barrel through the pipe and flows into the grow bed. 

It is essential to clean the barrel from time to time because of the solid waste that settled down at the bottom. Use only clean water for cleaning. Avoid using soap, as this may kill the bacteria.

  • Raft Water Filter

The raft filter is another way of filtering your system, where the solid waste passes through the two or three filter layers or chambers. The layers feature large pieces of foam that serve as filters. These foams are placed at the top of the tank through which the water passes.

The first filter layer collects solid waste particles before entering the nest filter layer. After the water passes through all the layers, the clean nutrient-rich water is then pumped into the grow beds for plant use. This type of filter usually uses large tanks and is often used for commercial aquaponics.

  • Chemical Filter

Chemical filtration converts ammonia into nitrate, which provides nutrients to the plants. In aquaculture, the amount of ammonia, nitrite, and nitrate in the tank is reduced through regular water changes. However, in aquaponics, you can save water since you won’t need to change the water often as your plants feed on the nitrates in the water. 

  • Biofilter

Biofiltration assists in the aeration and nitrification process of your system. An aquaponic biofilter is a place for the beneficial bacteria to colonize. It provides large surface areas, pH, dissolved oxygen levels, and proper temperature.

Your whole aquaponics system is a biofilter. However, if you are using the DWC, Vertical, and NFT aquaponics system to grow your plants, you will need a biofilter. In these types of systems, you can't rely on the natural process of bacterial conversion because of a lack of adequate surface area.

A media-based or raft aquaponics system does not usually need a separate biofilter because the raft, growing media (expanded clays, gravel, or lava rock), tank walls, and other surface areas provide enough area for the beneficial bacteria to colonize.

Biofilters are quite simple to set up, and they consist of a tank connected to the air pump and some substrates that provide as much as possible a big surface area for the nitrifying bacteria to grow. To learn more about aquaponics biofilter in aquaponics, click here

Ways to Prevent The Need to Use Water Filters in Aquaponics

If you plan to raise a lot of fish and want to ensure the stability of your system, adding water filters is an excellent investment. But there are ways in which you can eliminate the use of filters in your system; these are:

Conclusion: Do Aquaponics Systems Need Water Filter?

A good filtration system can help ensure that your aquaponics system is functioning well and stable. Water filters are unnecessary if your system has low livestock density or enough surface area to promote healthy bacterial growth.

However, if you have too many fish in your tank or plant to raise more fish, it is better to invest in a good quality filtration system to ensure the continued stability of your aquaponics system.

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1 Response



July 24, 2022

Thank you, it can be a provision for me to start building an aquaponics business. Regards

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