What Is An Aquarium Filter Bag?

3 min read

Hello, fellow aquarists!

Welcome to the dark side ahem, I mean the boring side of aquariums.

Although fish are beautiful creatures that are relaxing to watch, there are some boring subjects you must study to keep your aquarium in tip-top shape.

One of these so-called boring subjects is aquarium filter bags! Duh duh duh duh! (Drumroll).

An aquarium filter bag is a bag that holds filter media that grabs chemicals or small pieces of debris from your aquarium water as the water passes through. Aquarium filter bags are housed in your filter and keep the filter media from escaping or mixing together.

Let’s dive in and get to know the different kinds of filter bags…

Our Top Choice For Aquarium Bags!...

AquariumFilterBags PetAquariums What Is An Aquarium Filter Bag?

How Do You Use An Aquarium Filter Bag?

With any type of aquarium filter bag, it is very important to make sure the bag containing the filter media is barely bigger than the filter opening.

This causes a good seal once you put the aquarium filter bag into the filter. This way, water is forced to travel through the filter bags and not around them.

Pre-Made Aquarium Filter Bags

The easiest aquarium filter bags to use are the pre-made bags you can buy. These are usually sealed shut though so you can’t replace the filter media. These bags can be expensive though so other options are available.

Reusable Aquarium Bags

You can buy these bags and the filter media separately, which ends up being cheaper in the long run.

Again, make sure to measure your filter and the bags so the bags are barely bigger than the filter for a good seal.

These bags are usually drawstring, zipper, or velcro. Some people make DIY bags out of things like cheesecloth or pantyhose.

Simply place some filter media inside, zip tie or velcro, and then place the bag in your filter tray.

AquariumFilterDiagram PetAquariums What Is An Aquarium Filter Bag?

If you get zipper bags, make sure the zipper is plastic so it doesn’t rust.

With the velcro bags, make sure too much gunk doesn’t build up in the velcro.

What Can I Use As A Filter Media Bag?

You can use the pre-made filter bags, refillable filter bags, or DIY aquarium bags

What Are Aquarium Filter Bags Made Of?

These bags are usually made from nylon or polyester. If you venture into the DIY bags, they have been made from pantyhose, cheesecloth, and paint strainers with zip ties.

Filter media to fill the bags is usually ceramic rings, carbon pieces, bio balls, or zeolite.

DIY filter media that have been used to fill the filter bags: crushed coral, and lava rock.

Chemical Filter Media:Mechanical Filter Media:
CarbonCeramic Rings
GFOFilter Floss
Resin MediaFelt Polishing Pods
MixedCoarse Sponges
PurigenFilter Socks
ZeoliteLava Rocks

Our Top Choice For Chemical Filter Media!…

Our Top Choice For Mechanical Filter Media!…

DIY Aquarium Bags

I personally don’t think the reusable bags and filter media are very expensive but I only have one aquarium.

Some people who have several aquariums may try to go the DIY route as much as possible, even to the point of using old pantyhose as aquarium bags.

All you do is cut the pantyhose, seal one end by tying, a rubber band, zip tie, etc. Fill with filter media and seal the other end.

Cheesecloth has been used by stacking layers, wrapping them around the filter media, and then sealing them with a knot, rubber band, zip tie, etc.

You can use a paint strainer which is usually made out of nylon. It is already shaped like a bag, so all you have to do is cut it to size, fill it with filter media and seal it with a knot, rubber band, zip tie, etc.


Depending on how much time you can spend on your aquarium, you might want to spend the extra money to get the pre-made aquarium bags.

We’re not talking hundreds of dollars here but we are talking 10-20 dollars for one bag that you have to change about once a month.

You can spend the same on reusable bags and have enough to last for several months but you will have to store the bags and filter media. You will also have to fill and tie the bags.

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Pet Aquariums

Have you any questions?