Are Water Filters Needed in Aquaponics?

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A successful aquaponics system relies on the symbiotic relationship between fish and plants. The healthier the fish, the better it is for the crops, and vice versa. And while aquaponics is naturally self-sustainable, and is already a filter on its own, many practitioners use supplemental equipment like water filters to enhance the system’s performance. This leads to more growers to wonder, are water filters needed in aquaponics, or will the system itself do the job? 

Water filters are not necessary for an aquaponics system. However, adding a filter may improve the health of your fish and plants. It is also crucial to know the difference between mechanical filtration from biological filtration. These two, while both can help in maintaining good water quality, have different purposes. 

In this article, we will share how aquaponics water filters can help your system, the types of filtration and its benefits, and how to create one using simple materials. 

What is an aquaponics water filter? 

An aquaponics water filter is a supplementary tool that helps in removing hazardous substances, decaying organic matter, excess food, and fish waste from your fish tank. As aquatic creatures consistently produce wastes while they swim in the tank, toxins may build up over time. If these will not be removed, it can cause ammonia stress, which could lead to ammonia poisoning. 

Effective Water Filtration 

Effective water filtration is achieved by using both mechanical and biological filters. Let’s examine some of the major differences between these methods in the table below:  

Method	Purpose
Mechanical filtration	Filters large solid particles to avoid clogging. You can use materials like sponge or screens.
Biological or Biofiltration	Assists in the aeration and nitrification processes of your aquaponic’s system.

Simply put, mechanical filtration aims to provide clearer water. It ensures that the water will easily flow through the system by preventing large particles from clogging pipes. On the other hand, using a biofilter is a more complex concept, which we will discuss in detail in the latter sections. 

Why is an aquaponics water filter needed?

Fish excrete ammonia through their urine, gills, and when their solid wastes break down. Even at low levels, ammonia could be toxic to most aquatic creatures. Since fish in tanks are stocked densely, this could lead to higher levels of ammonia than in ponds or lakes. This is one of the reasons why a water filter is highly recommended for aquaponics. And while some practitioners do not agree with this, many growers nowadays can see its benefits. 

Here are the other reasons why you should consider using an aquaponics water filter:  

Optimal Fish Environment 

An aquaponics water filter helps in maintaining a clean environment for your fish. By removing dirt, unnecessary substances, and chemical contaminants like lead and mercury, your livestock could avoid diseases caused by polluted water. 

Remember, providing the highest quality of fish feed will not guarantee optimal health for your fish. More than that, you need filtered water for them to thrive. 

Healthy Plant Growth 

When you filter the water in your aquaponics system, it becomes more suitable for your crops. Unfiltered water could contain high levels of pH, which can also affect the growth of your plants. 

Sustainability 

You can minimize overall water usage by adding a water filter to your aquaponics system. This strengthens the core objective of using an aquaponics system as an eco-friendly solution for farming. 

What is an aquaponics biofilter?

An aquaponics biofilter is designed to help in converting the ammonia into nitrates that your plants can use for optimal growth. It provides an environment for beneficial bacteria to live in. To further understand its role, let’s highlight the importance of healthy bacteria in your aquaponics system.

Healthy Bacteria

Healthy bacteria are necessary to convert ammonia to nitrites and then to nitrates. However, if your grow media doesn’t have enough surface area, there won’t be sufficient beneficial bacteria for your plants. What a biofilter does is to provide an additional surface for bacteria to attach. 

How to build an aquaponics biofilter 

You can build your aquaponics biofilter tank from easy-to-find materials. In this section, we will share with you one of the simplest ways to do it. This design has both mechanical and biological filter properties. 

Materials: 

• PVC pipe 
• Bucket or Tub 
• Screen 
• Mesh 
• BioBalls/ Expanded Clay 

Instructions: 

Step 1. Create a hole on the upper portion of your bucket where you can attach the PVC pipe. This is where the water from the fish tank will flow. 

Step 2. Create another hole on the other side of your bucket. This should be at the lower portion where the water goes from your biofilter tank to your plant culture bed or grow media. 

Step 3. Place your biofilter media at the bottom of your tub. You can use expanded clay, or you can purchase bioballs. These are efficient and could grow more beneficial bacteria. You may get it from here. 

Step 4. Add your mesh that acts as another filter to screen smaller particles. 

Step 5. Place your screen on top of the mesh to filter bigger solid wastes.

Step 6. Install your DIY biofilter tank between your fish tank and grow media to start filtering.  

Where to buy an aquaponics biofilter

Several manufacturers have released their own models of biofilters. However, these are not created equal. That is why we searched for the most sought-after aquaponics biofilters to narrow down your choices. This list is based on the equipment’s features, effectivity, cost, and user reviews.

• OASE BioSmart 10000 Pond Filter from here
• Aquascape Submersible Pond Water Filter from here
• TetraPond Clear Choice Biofilter from here

Before you purchase your aquaponics biofilter, we recommend checking the equipment’s capacity and warranty. At an average, manufacturers provide a 3-year warranty for all new items. However, this may vary depending on the manufacturer and the biofilter model. 

Conclusion: Are Water Filters Needed in Aquaponics? 

Not all aquaponics systems need water filters. If you have a low density of livestock or enough surface to promote healthy bacteria, water filters are unnecessary. However, if you plan to raise a lot of fish and would like to ensure that your system will be at its best, adding a biofilter is a good investment. 

There are also ways to minimize the waste found in your water. This way, your biofilter will not have to work twice as much. Thus, it could last longer. Here are some of our tips:  

• Avoid using cheap feed as the fish will not be able to digest it fully
• Regulate the amount of your fish feed since too much will turn into waste
• If possible, keep your fish density towards the lower end of the recommended range