Biofilter in hydroponics: Why it is important and how to make one 🌿💧

Biofilter in hydroponics: Why it is important and how to make one 🌿💧

What is a biofilter and why do we need it in hydroponics?

If you grow plants in a hydroponic system and use organic fertilizers (e.g. Terra Aquatica TriPack Organic), you will definitely come across the recommendation to add a biofilter to the system. But why?

A biofilter is a device that allows beneficial microorganisms to live and multiply – such as those found in products like Trikologic . These microorganisms help break down the organic matter in organic fertilizers and convert them into forms of nutrients that are easily absorbed by plants. They also stabilize the environment and prevent cloudiness or odor.

Without a biofilter, organic nutrition in the aquatic environment can:

• clog pipes and pumps
• create an anaerobic (oxygen-free) environment that promotes rotting
• slow down the absorption of nutrients by plants

How does a biofilter work?

A biofilter is a space where water slowly flows through a filter medium (such as expanded clay, bio balls or foam) that has a high surface area for microorganisms to attach to. The water is also oxygenated , which promotes healthy aerobic microflora.

The result? The water is “biologically active” – clean, odorless and full of available nutrients.

How to make a simple biofilter for hydroponics at home 🛠️

What you will need:

• A 3-5 liter container – ideally plastic with a lid
• Filter medium – expanded clay, bio balls, or larger foam cubes
• Air stone + air pump – for water oxygenation
• Water supply and drain – hoses or connectors, depending on the system
• Optional: mesh or grid to keep the media from shifting

Procedure:

1. Filling the container with filter media – up to 3/4 of the volume.
2. Placing the aeration stone at the bottom and connecting the pump.
3. Ensuring water inlet and outlet – water should flow slowly, ideally using a pump.
4. Let it filter for at least 24 hours before adding to the main circuit – microorganisms need time to activate.

Tip: Check the water flow regularly, the filter media does not need to be replaced often - only if it is heavily clogged.

Here is a simple sketch of a homemade biofilter for hydroponics:

• The container serves as the filter body (e.g. a bucket with a lid)
• Inside is a filter medium (expanded clay or bio balls) that provides space for beneficial microorganisms
• Below is an aeration stone that ensures oxygenation of the water
• Water flows from the tank, flows through the filter and, after purification, flows into the growing system.

Summary

Using a biofilter is key to success in organic hydroponics. It allows you to fully utilize the benefits of organic fertilizers, stabilizes the system, and protects your plants from problems caused by the accumulation of undigested organic matter.

A biofilter is easy to make, inexpensive, and can significantly improve the performance of your system. If you grow organically, it's a small step with a big impact. 🌱