Revolutionizing Hydroponics: Harnessing the Power of Aquarium Filter mats as the Ultimate Growth Medium

Discover the Advantages of Using Aquarium Filter Mats for Hydroponic Plant Growth

Tim Adelmann 26.08.2023


In the ever-evolving world of hydroponics, where innovative techniques drive the growth of plants without reliance on soil, the significance of the right growth medium cannot be overstated. Traditionally, materials like perlite, coconut coir, and rock wool have taken center stage, providing essential support to the plants as they thrive in nutrient-rich water solutions. However, a new and intriguing player has emerged on the hydroponics stage – one that might just redefine how we nurture our leafy companions to their fullest potential.

Imagine a growth medium that not only encourages healthy root systems but also prevents the bane of many hydroponic growers: mold. Envision a substrate that effortlessly accommodates the growth of seeds into robust seedlings, making transplanting a breeze. Enter the world of aquarium filter mats – an unconventional yet promising growth medium that promises to revolutionize the way we approach hydroponics.

In this article, we’ll delve into the hidden benefits of using aquarium filter mats as a growth medium for hydroponic plants. From their exceptional breathability that curbs mold growth to their root-penetrable structure that fosters nutrient absorption, and their unique suitability for seed propagation, we’ll explore how these unassuming mats are reshaping the hydroponic landscape. Get ready to uncover a new dimension in plant cultivation that might just be the missing piece in your hydroponic puzzle.

Unveiling a Hidden Gem: Aquarium Filter Mats

Ebb-flow system with aquarium filter mats as growth medium

Ebb-flo system with aquarium filter mats as growth medium

While designing my latest Hydroponics system I was looking for a growth medium that does not mold, allows for root breathability, and small seedlings to grow through. My latest attempts showed that access to water for seeds and breathability is often not equally achievable.

That’s where I tried a new growth medium: Aquarium Filter mats they are porous to allow water, air, and seedling roots to run through. Also, it was important for me to be easily able to transplant the plants into a bigger system once they have a reasonable size. With these filter mats, I can easily cut out the plants or even pull out the plants entirely.

Coming from an NFT background, I knew that the go-to solution for netcups is a sponge-like material anyway, so using a big sponge-like material seemed like a perfect solution.

Aquarium filter mats, originally designed for water quality maintenance in aquariums, seamlessly translate to hydroponic systems. These mats, which aid in debris trapping and microbial growth in aquatic environments, offer a parallel solution in hydroponics. By providing a stable foundation for plant roots and aiding nutrient access, these mats align with the core principles of both aquatic and hydroponic growth, making them a promising innovation for modern plant cultivation.

Advantages of Filter Mats

Mold Prevention Through Breathability

aquarium filter mats as growth medium in hydroponic setup without mold

Even in a system with a lot of smaller plants there is no mold on top of the growth medium

Water plays a big role in hydroponics, whereas the plant roots are constantly under water to extract nutrients. Unfortunately, water and moisture often attract mold, especially when no air flow is provided to plants, the growth medium is subject to mold. Mold can be very dangerous for hydroponics, it can affect the plants and lead to root rot and other plant disease. And who wants to eat fruits of plants which are infected by mold?

Aquarium filter mats solve that problem by allowing proper air and water circulation. Excess water does not stay on top of the filters, so it dries very fast through the various filter mat pores. Most of the time it’s the excess water that creates moisture and thus mold.

I tried a lot of different growth media in my system, but high humidity and excess water led to mold very often. Aquarium filter mats solved that issue entirely. Apart from grown-up plants, I was looking for a medium that supports propagation.

Ideal Medium for Seed Propagation

seed propagation with aquarium filter mats in hydroponics

seed propagation with aquarium filter mats in hydroponics

In the past, I tried, pebbles, soil, coconut coir, and sponge as a propagation medium. All of them had problems:

  • Soil and Coconut coir: mold was a big problem, also it cannot be easily automated, because soil in a hydroponics system is dirty and might eventually clog the pump. Propagation in an external soil-based environment works better, but the transition to hydroponics is effortful.
  • Pebbles: The seeds were on top of the pebbles and never got any water to start their growth process. Putting them underneath the pebbles just drowns them and they will never propagate
  • Sponge: Putting the seeds on top, leads to the same problem as with pebbles. putting them inside or underneath also leads to the problem, that the plants are not powerful enough to pierce the sponge with their roots and leaves.

Aquarium Filter Mats solve all of these problems. There is no mold, water rushing through it does not pollute the system, and plants can easily propagate through. And the best thing is, because of the porous nature seeds can be within the mats, getting access to water but also air. When flushing in an ebb-flow system, it works perfectly. The seeds can fall through, and the pores small capture water drops for the seeds to access.

Seeds hanging in the filter mat with access to both water and air

Seeds hanging in the filter mat with access to both water and air

When it comes to transplanting, usually you need to extract the plant from its propagation medium to put in your regular hydroponics medium. With filter mats, it’s easier to extract them or you can simply cut them out around the root and transplant with the medium into another system.

Root Penetration Made Easy

small plants pinching through aquarium mats in hydroponics

small plants pinching through aquarium mats in hydroponics

Additionally to the propagation advantage, even bigger plants can effectively penetrate the whole filter mat with their roots, giving them plenty of foothold. Also access to nutrients is easy, and can reach every part of the extensive root system.

Even bigger plants can effectively penetrate the filter mat

Even bigger plants can effectively penetrate the filter mat

Easy Procurement

Filter mats are available in vast supply and purchasable even through Amazon. They are cheap to get even in big quantities, making them sometimes even cheaper than clay pebbles.


No natural resource

The only disadvantage of these filter mats is that they are not natural. I believe there are natural alternatives like a coarse-grained sponge, but I haven’t used them yet. Also, a natural alternative might be much more expensive than these mats.


Comparison of filter mat top and regular pebble-based growth medium bottom

Comparison of filter mat top and regular pebble-based growth medium bottom

As you can see in the picture above, filter mats allow for a more equally spread plant distribution whereas with pebbles there are fewer smaller plants. Most likely the seeds in the pebble-based system did not germinate at all or were washed away by the water. I now fully transitioned the system to filter mats, and will likely transition all my systems to it.

Getting Started: Using Aquarium Filter Mats in Your Setup

small plants pinching through aquarium mats in hydroponics

small plants pinching through aquarium mats in hydroponics

It’s easy just buy some filter mats, and try it out. I started with filter mats that have 10 PPI (Pores Per Inch) it worked perfectly, if you have really small seeds you could also layer the mats on top, where a finer-grained mat goes underneath and a more coarse-grained mat on top. The coarse-grained mat facilitates plant growth and the fine-grained mat prohibits the seeds from being washed away. Mats can be easily cut with a regular scissor, and are cheap to purchase


I am very glad that I found this growth medium, I experienced problems with mold and propagation in general, and aquarium filter mats seem to solve both issues for me. I will of course test out new mediums in the future, but for now, these filter mats are set. I’m even convinced they can be reused next season, but I have not tested this. All the advantages mentioned above make it the perfect medium for me. You should try it too!

I encourage every hydroponics enthusiast to explore new alternatives for growth media, even unconventional choices can yield better results. Experiment with your systems. In the end, hydroponics is about unconventional farming and experimentation is a big part of it.