How to Maintain Your Aquarium Filter: Cleaning Tips for Every Type
Cleaning your aquarium filter is essential for keeping the water clean and balanced and keeping your tank's inhabitants happy and healthy.
The filter plays a crucial role in removing dirt, debris, and fish waste while also oxygenating the water and supporting the nitrogen cycle. But filters can become clogged without regular cleaning, which reduces their effectiveness at cleaning the water, potentially harming your fish.
In this guide, we’ll walk you through the proper cleaning techniques for various aquarium filters, including hang-on filters, sponge filters, canister filters, under-gravel filters and in-tank filters, ensuring that you keep your tank in top condition.
Table of contents
How to clean under gravel filters
Top tips for cleaning your aquarium filter
How to clean your aquarium filter
Cleaning your filter involves removing debris and decaying organic matter while preserving beneficial bacteria that support the tank’s ecosystem.
- Do it in a way that doesn’t remove too much beneficial bacteria.
- Avoid tap water, and never use soap or bleach.
Each type of filter requires different cleaning techniques, which we’ll cover below.
Canister filters
Canister filters are enclosed. They can go the longest between cleans.
How often should you clean a canister filter?
Clean a canister filter every 4-6 weeks.
How to clean a canister filter:
- Unplug the filter and remove any other equipment that may be attached, such as an inline heater. We recommend unplugging the heater several minutes before the filter so that it has a chance to cool down.
- Fill a bucket with water from the tank and empty the filter media for cleaning. It’s important to keep the filter media wet to not dry out and kill the beneficial bacteria.
- Use a soft-bristled brush to scrub the impeller, hoses, and any other small parts.
- Reassemble the canister once it is completely clean, and fill it with tank water before reassembling it and turning it back on.
Under-gravel filters
If you have an under-gravel filter, you should clean it regularly, including the overlying substrate.
How often should you clean an under-gravel filter?
Clean your under-gravel filter every 1-2 weeks for gravel vacuuming and conduct full maintenance every 6 months.
How to clean an under-gravel filter:
Coordinate cleaning your under-gravel filter with your routine water changes.
- Use a gravel vacuum during water changes to remove debris.
- Periodically lift sections of the filter plate to clean beneath it.
Refill the tank with freshwater using a suitable de-chlorinator.
Sponge filters
Different sponge filters require different maintenance. However, the most popular type of sponge filters are powerhead or pump filters.
How often should you clean a sponge filter?
Clean a sponge filter every 2 weeks.
How to clean a sponge filter:
- Disconnect the filter from the power source.
- Rinse out the service lines to remove any debris buildup.
- Rinse the sponge in a bucket of tank water to clean it and remove any solid debris.
Never let the sponge dry out, as this can remove good bacteria and cause more harm than good.
Hang-on filters
Hang-on filters are popular for their ease of use but can quickly accumulate debris in the cartridge.
How often should you clean a hang-on filter?
Clean a hang-on filter every 3-4 weeks.
How to clean a hang-on filter
The process for cleaning hang-on filters is generally similar to the processes for canister and sponge filters.
- Disassemble the filter and scrub the impeller, intake tubes and other small parts using a soft brush.
- Rinse and clean sponges and biological media in a bucket of tank water.
Put the sponges back into the aquarium or filter after cleaning to prevent them from drying out.
In-tank filter
In-tank filters are very similar to hang-on filters. They are generally the easiest filters to clean.
How often should you clean an in-tank filter?
Clean an in-tank filter, ideally, every 2 weeks. Once a month minimum.
How to clean an in-tank filter
- Remove the filter from the tank and clean the sponges in a bucket of aquarium water.
- Replace the chemical filter media every 3-4 weeks, and simultaneously give the filter housing a rinse.
Clean any buildup of algae or debris that may have accumulated in the impeller housing to ensure optimal performance.
Top tips for cleaning your aquarium filter
Follow these best practices when cleaning out your tank:
- Use tank water: Rinse the filter media in a bucket of tank water, as this will preserve beneficial bacteria. Don't rinse it in tap water, as chlorine can kill these microorganisms.
- Clean parts separately: Disassemble the filter and clean each part individually, including the media, impeller, and tubing.
- Avoid over-cleaning: Don't scrub too aggressively or replace all the filter media at once, as this could disrupt the nitrogen cycle and harm water quality.
- Check performance: After cleaning, reassemble and test the filter to ensure it's working properly.
FAQs
How do I know when to clean my fish tank filter?
Signs that your filter needs cleaning include:
- Reduced water flow or filter efficiency.
- Unpleasant odours in the tank.
- Visible debris buildup
- Declining water quality, such as cloudiness or algae growth.
What happens if you don’t clean your tank filter?
Tank water becomes dirty when fish waste and debris break down.
Failing to clean a tank filter can lead to:
- Clogged filter media, reducing water flow and oxygenation.
- Accumulation of harmful toxins that can be deadly for aquatic life.
- A shortened lifespan of the filter system.
How often should you clean a fish tank with a filter?
The frequency of how often you should clean your tank filter depends on:
- The size of your tank
- The type of filter
- The amount of fish or aquatic life you have in your tank
- The amount of waste produced by the fish.
Typically, a partial tank cleaning every 1-2 weeks is sufficient, while filters may require attention anywhere from every two weeks to several months, depending on their type.