DIY Aquarium Filter

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DIY Aquarium Filter

Aquarium filters maintain a healthy aquatic environment by trapping waste and uneaten food. Keeping a clean and quality filter in an aquarium at all times is critical to ensure healthy fish. Filters come in various sizes and the cost of replacing them is often expensive, but those looking to save money can opt to build a filter rather than buy one. Buyers can find the necessary supplies at retail pet shops, or browse the large selection offered on eBay at affordable prices. By learning the supplies needed and the steps to follow, building an aquarium filter is simple as well as budget-friendly.

Types of Filters

Box filters and sponge filters are perhaps the two easiest and most inexpensive types of filter to build. The supplies required for both are minimal and only a short amount of time is required.

Sponge Filter

Sponge filters are an excellent choice for keep an aquarium clean. By gathering a few simple supplies and following some steps, building a filter that is effective and cost efficient is easy.

Supplies Needed

To build a sponge filter, a 10- to 15-cm sponge that is clean and free of debris is required. The sponge should be made of open cell foam for best results. Other supplies include 12 mm tubing, activated carbon, fine mesh, a submersible water pump, and an open-top container, such as a water or soda bottle.

Building the Filter

Do-it-yourselfers should take the open topped bottle and fit the pump inside. Pour a small amount of the activated carbon into the bottle and wrap the pump intake valve with a small piece of mesh. Do-it-yourselfers should then take the 12 mm tubing and attach it to the outlet valve on the pump. Cut the sponge into small pieces and add it piece by piece to the open bottle in order to surround the tubing. Finally, hang the finished filter on the side of the tank. Using a suction cup or wire is the easiest way to keep it in place.

Box Filter

Box filters keep the aquarium clean, but require more steps and supplies than a simple sponge filter. While the filter is perhaps more durable, replacing or cleaning it is more challenging. This type of filter needs replacement periodically throughout the year.

Supplies Needed

To make the box filter, the tops of two disposable plastic boxes are required. Food storage boxes are the easiest and most readily available to use; the taller the boxes, the better the filter. Additional materials include 12 mm tubing, silicone sealant, a submersible water pump, glass wool, charcoal, and a drill.

The Build

To build the filter, do-it-yourselfers take one box top and place two small pieces of the tubing on opposite sides of the bottom and secure them with sealant. With a drill, cut small holes in the box with the tubing. Repeat this step with the other top box while adding a 12 mm diameter hole in the middle for the tubing. Place glass wool and charcoal into the bottom box, ensuring that it covers the entire bottom.

Carefully place the cut box into the bottom box and insert another piece of tubing that has a sealed end into the top box, ensuring that it sits between the two boxes. Take a small, sharp object and place holes up the tubing line. Seal the boxes together with the silicone sealant. Hook the other end of the tubing to the water pump.

Finding the Right Filter

The type of filter needed depends on the size and the type of fish. While both work for most tanks, having the right filter ensures a healthy environment.


Aquarium Size

Types of Fish



10 gallons or less

Best for small or saltwater fish

Takes up less space


10 gallons or more

Best for breeder fish or larger species

Aesthetically pleasing

By learning about the different types of filters, it is simple to figure out which one is best for the tank in question. A quality filter is just one important aspect of having a clean aquarium.

How to Buy DIY Aquarium Supplies on eBay

Buying the supplies needed to build an aquarium is easy by shopping on eBay. With the ability to filter down results by size, condition, or price, finding what you need is simple and affordable. You can also use the search box to find the exact product you are seeking. Once you find what you want, buying from a top-rated seller is essential for a great experience.

For those looking to save money and keep their aquarium environment healthy, a DIY filter is the answer. With the know-how and a few supplies, the build is easy and can save you money.

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