How To Build DIY Aquarium Top Filter (Tank Overhead Filter):

Every aquarium needs a quality filter to keep the water quality clean and also maintain good health of the fish. Store bought filters can be efficient but they do not fit every aquarium. Building a DIY filter is very easy as long as you know the basics and are not shy of getting your hands dirty. DIY Aquarium top filters are more efficient than the conventional filters such as it can cut down the tank maintenance, can be easily modified and updated and could be turned into an aquaponic.

An aquarium top filter is sometimes also called an overhead sump filter if it can hold water. This video is a step by step and detailed tutorial on building a DIY aquarium top filter which would be able to hold water and will offer powerful mechanical and biological filtration capabilities to the entire system. We have provided all the steps required to make DIY tank overhead filter.

How To Setup An Aquarium Top Filter:

Check out the full tutorial about how to make top filter for aquarium:

How to make top filter for tank

I have added a step by step tutorial about how to setup an aquarium top filter with screenshots:

Step 1:

Canopy of overhead sump filter
Step 1: Overhead sump filter box

Find an appropriate container that can hold water and doesn't bow over time and most importantly something that would fit on top of the tank. Source all the plumbing supplies such as PVC pipe, elbow, connectors, gasket, bulkhead and test if it can fit together.

Bulkhead are expensive and can be burden on the pocket if bigger size is required for the aquarium top filter. I would suggest a cheaper option of going with male and female adapters with threads and buying a gasket.

Step 2:

Drill holes in the channel drain & tray
Step 2: Drill holes in the channel drain & tray

Drill holes for the inlet hose and outlet hose [a]. Connect all the plumbing to see if it fits [b]. Build a tray to mechanical filter media so it doesn't touch the water in the overhead sump [c].

Step 3:

Use silicone to properly seal all connection
Step 3: Use silicone to properly seal all connection

Use aquarium safe silicone to properly seal all connection [a]. Male and female adapters with a gasket doesn't need silicone but in my opinion silicone should be applied since these connections are permanent [b]. Connect the tray next to the hole for the inlet and take necessary measures to stop mechanical filter media from sliding off the tray [c]. There is no harm in using more silicone as it could be easily wiped off and since overhead filters are usually hidden under the canopy then could be left the way it is.

Step 4:

Fill filter with water to discover leaks
Step 4: Fill filter with water to discover leaks

Test the aquarium top filter for any leaks by filling it with water and leaving it for couple of days. It will also help in determining if the container is suitable to hold the amount of water. If there are any leaks, then they could be fixed by applying some more silicone. It is also a good time to adjust plumbing if required.

Step 5:

3 types of filtration are used including mechanical, chemical & biological. Mechanical filtration is the simplest type which is important for the health of the fish, & stability of the tank. It removes particles of uneaten fish food, fish waste, & other debris present in the water. Mechanical filtration is the first level of filtration process & should be placed next to the inlet. It also increases the colonization of good bacteria.

Foams can be used to provide better mechanical filtration. You can use 3 stages of foams for best filtration. Water should hit foam first when it enters filter. Foams should be placed in this order: coarse, medium & fine which will ensure all debris from the water is removed before it leaves mechanical filtration zone.

Step 6:

Biological filtration lies at the very end & it is the most important component of the filter which changes ammonia (dangerous for fish) into nitrates (not that harmful), & it can be removed by changing water regularly.

Ceramic media used in the biological filtration includes Aqua One Ceramic Noodles [a], & Aqua One Premium Sub Ceramic Substrate [b].

Biological filtration generates biological stability in the aquarium by providing the best environment for beneficial bacteria. Aqua One BioNood Ceramic Noodles can be used in the filter because they are extremely porous & provides the best environment for growing beneficial bacteria. Aqua One Ceramic Noodles can be used in both fresh water & salt water tanks.

Aqua One Premium Sub Ceramic Substrate is a very porous biological media that offers the best environment for the generation of denitrifying bacteria. Sub Ceramic Substrates are very important for healthy & productive biological filters. Aqua One Premium Sub can be used in both fresh water & saltwater tanks.

I have used pre-cycled ceramic media [c] but it is recommended to wash fresh ceramic media before adding it to the filter.

Step 7:

Setup plumbing & stuff
Step 7: Setup plumbing

After finding no leaks in the sump, it is time to connect all the plumbing & stuff. I cut a small piece of PVC pipe to join the adapter to the elbow [a]. I cut another piece of pipe to attach it to the other side of the elbow that will go down the aquarium [b].

Step 8:

Connect filter to the aquarium
Step 8: Connect filter to the aquarium

My aquarium is pre-cycled & there is lots of good bacteria inside the filter media so I connected the filter to the aquarium [a] but it is recommended to cycle your aquarium first if you have not cycled it & allow good bacteria to grow inside the filter before adding fish to the aquarium.

Water from the aquarium will enter the filter through blue flexi hose [b]. After turning on the pump, you will see water flowing through the mechanical filtration dripping down the tray which creates disturbance on the surface level of the filter, & enhances the oxygenation of water, & helps bacteria colonies to grow. The water is flowing down the outlet with a good flow rate & the sump is not filling up which is a good news.

Not all the biological filter media present in the bags are fully submerged in the water [c] which is not a big deal because I have heaps of bio media in the sump.

I connected the lid to the filter [d]. Since I have moved the biological filter media & disturbed the bacteria colonies so I have added some live bacteria to the aquarium & to the filter as well.


  1. A container that can hold water
  2. Aquarium Safe Silicone
  3. PVC pipe and 90 degree elbow
  4. Male and Female adapters with a gasket or bulkhead


  1. Electric Drill with paddle bit/drill bit or Soldering Iron

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