What’s your filter for?

An aquarium filter has several jobs to do, but its main purpose is to keep your aquarium clean, clear and healthy for your fish.

An aquarium is a closed system, so dirt and waste remain in the aquarium, turning it into a poisonous sewer without our intervention. This is why a filter is one of the most essential pieces of equipment in your fish tank.

It acts like a mini sewerage treatment works, and cleans up the aquarium water in several ways:

Your filter will remove dirt particles from the water. Cleaning you filter every month removes the dirt to keep things running smoothly.

Friendly bacteria – the majority of which live in the biological media in your filter – processes waste compounds to stop them poisoning the fish. See – Understanding the Nitrogen cycle.

Your filter will remove algae food, harmful metals, toxins, nasty odours and organic dyes for crystal clear, healthy water.

Your filter will move water around the tank to help add essential oxygen and remove carbon dioxide.


How do I choose an appropriate filter for a fish tank?

Choosing the right aquarium filter for your fish tank can be difficult. The size and type of fish tank you have will determine the type of filter you need.

Smaller tanks or tanks with fewer fish may require a simpler filter, while bigger tanks with more fish will require a more powerful filter. When choosing an aquarium filter, consider the size of the tank, the number of fish and the flow rate.

A power filter is often the most popular, as it is easy to maintain and keep clean. Hang-on-back filters are also good for smaller tanks, as they are affordable and easier to manage.

How do I set up an aquarium filter?

Setting up an aquarium filter is relatively easy and straightforward:

First, make sure you have all the necessary components: filter, tubing, airline, heater (if necessary) and a water conditioner.

Next, connect the filter to the tubing and air line. Then connect the air line to an air pump or power head. You may need some additional attachments to ensure proper connections between the components.

Finally, attach the filter to your tank, following the instructions provided with your filter. Once you have installed the filter, turn it on and make sure it is running correctly. Check for any air bubbles that may be entering the aquarium from the filter.

How often should I clean my filter?

It’s best to clean your filter every month. This will help keep it running efficiently and remove any dirt or blockages. However, always check your filter daily to make sure that it is functioning properly.

Can I turn my fish tank filter off at night?

It’s not recommended to turn off your aquarium filter at night. Keeping the filter running continuously is essential for maintaining water temperature and chemistry stability in the tank.

It also ensures a consistent flow of oxygenated water, which is essential for the health of the fish. Turning off the filter can disrupt the beneficial bacteria that help keep the aquarium environment healthy.

How do you tell if your fish tank filter is not working?

If your fish tank filter is not working properly, you may notice a few signs such as:

  • Cloudy or discoloured water. There may also be an unpleasant odour coming from the tank.
  • Humming or gurgling sounds coming from the filter
  • Improper flow rate
  • Loss of suction or no suction at all
  • An increase in algae growth
  • Unhealthy looking fish or fish acting strangely

If you notice any of these signs, it’s important to check your filter immediately and make sure it is running correctly.

Do you need to cycle a tank if you have a filter?

Even if you have a filter, you should still cycle your aquarium. Cycling helps establish the nitrogen cycle and bacteria which help break down waste and keep the water clean.

Without cycling your tank, the filter will not be able to keep up with the amount of waste produced by fish and other inhabitants in the aquarium.

So, take good care of your filter as it is the life support of your aquarium.

Here are some of our top tips for good filter care:

  • It can take up to 8 weeks to establish the biological system in a new aquarium. Add Fast Filter Start to help improve this process.
  • Check your filter every day. Check it’s working properly and clear any dirt or blockages.
  • Look out for evaporation and keep your aquarium topped up to the maximum water level. Always use Bioactive Tapsafe when adding new water.
  • Follow recommended cleaning and maintenance routines – See weekly and monthly care.
  • Add a filter booster treatment, such as Fast Filter Start, when starting your aquarium and when adding new fish.
  • Never clean the biological media in tap water. If it needs a clean, swill the media cartridge in a bucket of aquarium water (when doing a water change).
  • Regularly test your aquarium water. Most problems come from invisible toxins building up; this cannot only damage your fish, but may also cause filtration problems.
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