Choosing the Right Pond Filter Media for a Clean Pond
by Tory Jon | Last Updated: October 06, 2024
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A pond filter is essential for keeping your pond water crystal clear.
But your filter is only going to be as effective as the media you put in it.
A pond filter with subpar media will leave you with subpar results.
So, in this guide, we want to show you the best pond filter media options available today.
And answer all your yearning questions in our ultimate guide to pond filter media.
Media Comparison Chart
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Aquatic Experts Fine Classic Pond Filter Pad
The Aquatic Experts fine filter pads (and really all of their filters) are one of the most popular and highly rated pads available.
Proudly made in the USA, they feature unique latex-coated fibers to increase durability, making them ideal for handling heavy solid waste in outdoor ponds. And the open fiber construction allows for higher water flow without clogging, ensuring crystal-clear water, which is exactly what we want.
Designed specifically for koi ponds (so you know they will work in any backyard pond), the 1-inch thick Classic White Fine Pond Filter Pads provide excellent mechanical filtration. They work well with the black coarse filter pad and serve as a reliable replacement filter for your current setup.
These filter pads can be easily cut to any size, saving money compared to pre-cut filter media. The pads are reusable, easy to clean, and resist warping, breaking, and tearing.
Tips:
- Allow water to flow through a coarse filter pad first to trap larger debris, then through the fine filter pad. This helps prevent the fine pad from clogging too quickly.
- Use a cardboard template of your old filter and cut the new pad with strong scissors or a utility knife for a perfect fit.
Specifications
- Type: Mechanical media
- Material: 100% polyester
- Size: Various sizes available
- Cleaning: Easy
Matala Green Pond Filter Media Pad
Matala is the leader in pond filter media and is known for making some of the most durable filters and pond products on the market.
Their medium density green filter pads provide excellent mechanical filtration and provide enough surface area to be used as effective biological filters, as well.
These filters come in sheets that are 24 inches wide by 39 inches wide and are 1.5 inches thick. They can be easily cut with a sharp knife to fit perfectly inside your filters box.
Matala filter media is available in varying densities, and for best results, you may want to layer this medium density pad with a higher and or lower density for optimal filtration results.
Specifications
- Type: Mechanical & biological media
- Material: Medium density polypropylene blend
- Size: 24” wide x 39” long x 1.5” thick
- Cleaning: Easy
LTWHOME Fish Pond Foam Filter Sponge Set
The LTWHOME Pond Filter Set comes with 3 different types of foam filters – 1 fine, 1 medium and 1 coarse – which when layered and used in conjunction in your filter box provides excellent mechanical filtration against large and small debris and particles.
The media sheets are 17 inches by 11 inches each and can be easily cut with scissors to fit perfectly inside your filter box.
The foam material also provides a decent breeding ground for beneficial bacteria to grow on. However, I wouldn’t rely on that as a replacement for a quality bio-filter if you want the best results.
Specifications
- Type: Mechanical media
- Material: Foam
- Size: 17” wide x 11” long x 1” thick
- Cleaning: Easy
EasyPro Bio-Balls Filter Media
EasyPro Bio-Balls are 1.5-inch plastic balls specifically designed to have maximum surface area for beneficial bacteria to grow on.
The set comes with 200 bio-balls that can be used as loose media or placed in the mesh bag that comes free with the kit. The mesh bag measures 12 inches x 18 inches.
The hard-plastic balls will not give or compact like foam and other soft media, which may help reduce “channeling” of water and debris around media.
EasyPro pond products are made in the USA.
Specifications
- Type: Biological media
- Material: Plastic
- Size: 200 – 1.5” balls
- Cleaning: Easy
Aquaneat Bio Ceramic Rings
Aquaneat Bio Rings are made of ceramic and feature a complex pore system that maximizes surface area for beneficial bacteria to grow on.
The hollow design of the rings allows water to easily pass through, maximizing the number of beneficial bacteria colonies which in turn will effectively remove harmful ammonia and nitrites from your pond water.
The rings measure 5/8 inch by 11/16 inch and come in an 8 inch by 5.5-inch mesh bag, which will fit nicely in your filter, canister filter, skimmer, or waterfall. The kits include 6 pounds of rings and 6 mesh bags.
Specifications
- Type: Biological media
- Material: Ceramic
- Size: 6 bags, each are 8” x 5.5”
- Cleaning: Easy
CNZ® Black Fish Tank & Pond Bio-Balls
CNZ Bio-Balls filter media are hard plastic balls designed for long-term use. In fact, you should never have to replace them unless you notice they are visibly damaged or destroyed.
The unique design of the balls along with the bio-sponge inside allows for maximum surface area for beneficial bacteria to grow on.
The balls are black in color, 1 inch in diameter, and come in a set of 50 along with a free mesh bag for easy handling.
Specifications
- Type: Biological media
- Material: Plastic
- Size: 1” balls, 50 per bag
- Cleaning: Easy
Aquacity Activated Charcoal Carbon in Free Mesh Media Bags
Aquacity activated carbon is phosphate free and safe for your ponds fish and ecosystem.
Chemical filtration, using activated carbon, is an often-overlooked aspect of filtering pond water, but activated carbon filtration is effective for removing pollutants, chemicals, odors and colors from ponds - all things that mechanical and biological filtration can’t remove.
The Aquacity activated carbon set comes with free 8 inch by 5.5-inch bags which hold about a pound of the carbon pellets. Simply place a bag in your filter, skimmer, or waterfall and it will start working. For most ponds, you’ll want to replace the carbon pellets about once a month. For exceptionally healthy and clean ponds, every other month will typically do.
Specifications
- Type: Chemical
- Material: Activated Carbon
- Size: 8” x 5.5”
- Cleaning: N/A
Types of Filter Media
Pond filter media comes in three main types, each with its own unique purpose.
Mechanical Filter Media
Filtration via mechanical media is simply the removal of debris from your pond water as it is pumped through the filter. Mechanical media generally comes in a pad between .5” to 2” thick that resembles foam or a sponge.
Mechanical filters trap small and large debris and thus must be removed and cleaned periodically.
In terms of thickness for mechanical media, 1-2 inches is preferred. You might be tempted to use a thicker and/or denser material, and while that may provide better water filtration, it can increase pressure build-up in your filter and reduce water flow.
It’s also a good idea to layer your mechanical media with varying density’s. A coarse layer will help catch large debris and a fine density layer will help trap the smaller debris. The trick is to put the coarse layer on top so it can catch the large debris and the fine layer on bottom so that any small debris that finds its way through the coarse layer will be trapped by the fine layer. This will ensure a good amount of water flow for a longer time between cleanings.
Biological Filter Media
Biological filtration is not a replacement for mechanical media as it's not designed to trap debris. It is designed, however, to remove harmful substances from your ponds water. The bacteria on bio media converts harmful ammonia and nitrites into harmless nitrates.
Biological media provides the home necessary for these beneficial bacteria to live on. In fact, they are designed to have a maximum amount of surface area to encourage these bacteria to grow on. Basically, the more surface area there is, the more bacteria will grow, which will lead to better filtration results.
Chemical Filter Media
Chemical filtration is an often neglected, but effective and important part of the filtration process.
This type of filtration removes harmful chemicals from your ponds water that mechanical and biological can’t. These include pollutants, pesticides, odors, organic proteins and more.
The best type of chemical media for your pond is activated carbon. Over time the activated carbon will help remove these chemicals before they can build up to dangerous levels.
What Type of Media Should I Use?
Now that we’ve covered the three types of media, which should you use for your pond?
While the answer really depends on the level of filtration you desire, I typically recommend using all three in conjunction. And at a bare minimum using mechanical and biological together.
By using a mixture of the three types of media you will potentially:
- Have better water clarity and cleanliness
- Remove a larger amount of debris
- Lower the number of harmful substances and chemicals in your pond water
- Increase beneficial bacteria levels
- Create and promote a healthier pond eco-system
How much of each you use is up to you and the level of filtration you desire for your pond. I recommend starting out with at least a few layers of fine and coarse mechanical media along with some biological media and seeing what the results are after a few weeks. If your pond is still murky then you may want to increase the amount of media in the filter. You’ll also want to ensure your pond pump is properly sized for your pond, as under-sized pumps may not cycle your ponds water fast enough. Check out our pond pump and filter calculator to make sure you have the right setup for your specific pond.
If you’re still having water clarity issues no matter how much media you use, then check out our guide on how to clear murky pond water. The issue might be bigger than just your filter and media.
How To Clean Pond Filter Media
Inevitably, there will come a time when you have to clean your pond filter media. Luckily, if you have a healthy pond, cleaning your media should only need to be done a few times a year. If you notice a drop in water flow from your pumps outtake, there are noticeable changes in your water clarity and/or there are strange odors coming from your pond, it may be time to clean your filter.
The easiest way to tell is to simply peak inside your filter and inspect the media. If you notice a thick layer of gunk and debris on your mechanical media, then it’s time to clean them.
Biological media, on the other hand, only needs to be cleaned if they are completely clogged up with gunk and large debris. Bio media will naturally build up a brownish colored bacteria on the surface, which is what they’re designed to do! Repeatedly cleaning bio media will only wash away these good bacteria which will defeat their whole purpose. Again, you only want to clean bio media if they are covered in debris and they can’t do their job.
How To Clean Mechanical Media
Mechanical media can be easily cleaned by removing them from the filer box and hosing them off with regular tap water. Don’t worry about washing away any beneficial bacteria since mechanical media is not designed to house them.
You want to make sure you remove all of the particles and debris from each layer of media. You’ll notice that the finer media may be harder to clean than the coarse pads because of the smaller pores. This is completely normal.
Once you’ve removed all the debris from the media and they are clean, you simply place them back in your filter box.
How To Clean Biological Media
As stated above, bio media only needs to be cleaned when it’s so clogged up with debris and gunk that it can no longer perform its job.
If this is the case, then remove the bio media from the filter box and rinse off in a bucket of pond water. By using pond water, any beneficial bacteria colonies that are living in your media will remain intact and healthy. Keep in mind, you may have to manually remove any blockages or excess gunk with your hands.
If you do use tap water to clean your bio media or feel like you over-cleaned it, you can always jump-start the production of bacteria by applying a beneficial bacteria product to your media.
Once water can flow through the media again you simply replace the media back in your filter box.
*Note: if your bio media is frequently clogging up, that may be the sign of a bigger problem, such as too small of a filter, excess algae in your pond, poor pond aeration. You’ll definitely want to identify the reason why and fix the issue ASAP.
How Often to Replace Pond Filter Media
- Mechanical filter media should last a few years if it’s high quality (like a Matala mechanical filter). And it may even last longer. Be sure to inspect your mechanical media every time you clean them for tears, frays or other damage. Or if you notice your filter just isn’t performing like it used to, it may be time to replace the media.
- Biological filter media is designed to last and rarely needs to be replaced in our experience. You should only need to replace this media if you notice considerable damage.
- Chemical filter media, on the other hand, needs to be replaced more often - typically once a month. If you have an exceptionally clean pond you may be able to get away with changing them less frequently – every two months or so.
What Is The Best Filter Media For A Koi Pond?
The best filter media for a koi pond is again, going to be a mixture of the three types – mechanical, biological and chemical – but, there’s one important element to keep in mind when dealing with koi ponds (or any large fish ponds).
And that’s the size of the filter! It’s important to understand that large pond fish like koi create a lot of waste. Especially if you have a lot of koi fish in your pond. Add to that the fact that their uneaten food just adds to the waste problem and well, you can see where I’m going. Basically, the waste in the pond can really start to add up, which can feed pond algae and lower oxygen levels and the domino effect starts to take off.
Because of this, you want to make sure you get a filter that’s appropriately sized for not only your pond but the fish load in it. The best filter setup in the world won’t help if your filter is severely undersized. So, check out our pond pump and filter calculator to make sure you have the right setup for your specific pond and fish load.
