Although your aquarium might be the focal point in a room, you only want to see your tropical fish swimming silently around their beautifully aquascaped home.
You certainly don’t want the ambiance ruined by a noisy filter.
But why is your filter tank so loud, and what can you do to fix it, reduce the noise level, and make your tank filter quieter?
Read this guide to learn the causes of loud fish tank filters and discover some top tips to fix the problem.
Why Is My Aquarium Filter So Loud?
There are several reasons why your filter is loud.
Your filter can become blocked with dirt, or the impeller could be faulty. Perhaps the water pump is defective, the water flow rate is incorrect, or it could be that your filter is incorrectly positioned in your aquarium.
An old filter unit can sometimes become noisy if it needs replacement.
To know how to solve the problem of a noisy fish tank filter, you need to discover the root cause of the problem.
The most common culprit responsible for a noisy fish tank filter is the presence of dirt and sludge inside the filter pump.
That’s often the case if you’ve forgotten to clean the filter. All that gunk and muck that accumulates inside the filter obstructs the water flow through the unit, causing the filter to become noisy.
How To Solve the Problem
Fortunately, it’s pretty easy to fix a dirty filter.
- Step 1 – Clean the unit
Begin by unplugging the filter and removing it from your fish tank.
Open the filter housing and take out the filter media and sponges. Use some old tank water to thoroughly wash the filter media and clean the inside surfaces of the filter box.
Do not use tap water to rinse your filter media!
The chlorine in tap water will kill the beneficial bacteria in the sponges, potentially leading to an ammonia spike in your fish tank.
- Step 2 – Clean pipework
Now, look carefully at the filter pipes and tubes. If they’re dirty, use a filter cleaning brush and old tank water to clean them.
- Step 3 – Replace filter media
Replace the filter media in the filter box, draining away any leftover water. If you have a chemical filter, remember to replace the carbon.
Put the filter unit back into your tank, plug it in, and switch it on.
The impeller is the small propeller-like piece of the filter that spins, pushing water through the filter media by centrifugal force. A faulty impeller will cause your filter unit to become noisy.
Sometimes, the impeller is noisy because it’s dirty and in need of lubrication rather than broken. That problem is easily fixed by lubricating the impeller to reduce friction.
Provided your pump and filter are working, albeit without making sounds, it’s likely the impeller needs greasing. However, not all lubricants are suitable for use in your aquarium, and some of their ingredients are dangerous for your fish and other livestock.
We recommend you use Vaseline or silicone oil to grease your filter’s impeller. Vaseline is safe for use in aquariums and should solve the problem of a sticking impeller.
However, if there’s still no water moving through the unit, the impeller is likely broken. In that case, you will need to buy a replacement and switch out the broken impeller for a new one. That’s a simple job that you can usually do without too much trouble.
Sometimes, a filter unit can move in the fish tank, causing it to become noisy. That’s especially common in aquariums with large, boisterous fish and internal box filters.
For example, I used an internal filter fixed to the glass for some years via plastic suction cups. Sometimes, my two very large goldfish would displace the filter while grazing on a patch of algae that grew underneath the filter box.
That created space between the tank glass and the filter. The filter equipment vibrated against the glass, creating a loud noise.
The best way to keep your filter quiet and prevent vibrations is to take a piece of aquarium sponge and use it to plug the space between the viewing panes and the filter box.
The sponge soaks up any movement and vibration, reducing friction and effectively stopping that irritating rattle.
Alternatively, you could consider replacing your HOB filter with a canister filter.
Faulty Water Pump
If your filter is making a buzzing noise, that could be serious, indicating a faulty water pump.
To check if the water pump is working, we recommend you manually pump the water without the filter. You should also reset the filtration system to see if the filter pump is functioning normally.
A noisy water pump can make different sounds for different reasons, including accumulated debris, defective parts, cracked casing, etc.
If the problem is related to a defective or faulty part, you’ll need to change it.
If you’re not confident about doing that, we recommend you consult an aquatic equipment specialist at your local pond or fish store. Unfortunately, it’s not possible to replace a defective part in some cases, so you’ll need to buy a new filter unit.
Incorrect Water Flow Rate
A fish tank filter contains many moving parts. When the filter is functioning normally, you’ll hear a very slight buzzing sound as those parts move.
That’s perfectly normal, and the sound is usually not intrusive or especially detectable above the usual background noises of your home.
However, if you set the flow rate too high on your filter unit, the additional pressure placed on the filter’s moving parts means that they have to work faster and harder to accommodate the faster flow. That often creates more sound.
If you set your filter to produce a moderate to average water flow, the filter unit will generate less friction and, therefore, make less noise.
If you decide to reduce the flow through your filter to reduce the noise the unit makes, you should do that in gradual stages.
If you decrease the water flow too much too quickly, that can compromise the filter’s functionality. In the longer term, that can lead to accumulations of toxins in the aquarium water that could stress or even poison your fish.
Upgrade Your Filter Unit
Of course, if you tried to solve your noisy filter problem by following the above tips without success, it could be that your filter unit has come to the end of its life and needs replacement.
Fish tank filter designs and parts are updated on a fairly regular basis by major manufacturers. Older designs and parts tend to be louder when compared with newer technology.
So, if you’ve had your filter for a long time, it could be that the filter is now outdated, and you need to replace and upgrade the unit.
If you have an older filtration unit, we recommend browsing the marketplace and choosing a modern filter with the most up-to-date parts and technology. When choosing your new filter, remember to consider your tank size, filter design, water volume, etc.
Do All Fish Tank Filters Make a Noise?
Unfortunately, no fish tank filter is entirely silent, despite what marketing companies would have you believe. However, your filter shouldn’t make more than a quiet humming sound when it’s working.
If you think that your filter unit is very noisy, you should investigate the likely causes, i.e., dirty components, faulty impeller, poorly positioned unit, and incorrect flow rate.
Ultimately, if you have a very old filter unit that’s recently become noisy, you might need to replace the unit with a new, more modern one.
Sometimes, a noisy fish tank filter can drive you crazy, especially if the tank is in your office and no one wants to listen to a noisy filter at night. But whatever you do, do not switch the filter unit off.
Your filter unit must run 24/7/365 to keep the environment safe for your fish. If the filter isn’t operational, ammonia and nitrite can build up in the water, presenting a hazard to your fish.
Aquarium Filter Waterfalls
If you have a HOB filter system, a power filter, or a bio wheel, the constant splashing made by the water returning to the tank can be quite annoying if the sound is too loud.
Waterfalls generally make a splashing sound when the water level in the tank is too low. That means the water has to fall further than is ideal.
Increase Water Levels
So, if you increase the water level in the aquarium, that can reduce the noise.
Since water evaporates from fish tanks pretty quickly, you’ll need to put in place a regular top-up regimen to maintain the water level and keep the splashing noise to a minimum.
Reduce the Flow Rate
Try reducing the flow rate through the filter system to prevent the water from falling into the tank too quickly.
That can also prevent noises made by a filter that’s running too fast, as described above.
Bubbling sonances are another normal sound you can associate with certain types of aquarium filters, especially sponge filters.
The best solution here is to make the air bubbles smaller by adding an airstone to the airline inside the foam filter media.
Using an enclosed tank lid or diverting the bubbles from the water surface can help to reduce the noise the bubbles make.
A noisy fish tank filter can be caused by loose parts vibrating inside the filter unit. Also, if the filter is not working properly, the filter media can get clogged with silt, causing the unit to vibrate as it struggles to push water through the media.
In both those cases, you need to establish the exact root cause of the noise and fix it.
External air pumps often start vibrating, especially if placed on a table or cabinet shelf. One simple solution that prevents that is placing the pump on a sponge or some absorbent material to muffle the noise.
Alternatively, you can hang up the pump so that it doesn’t come into contact with any solid surfaces. If the pump is hanging against a surface, pad it with a piece of sponge.
In this part of our guide, we answer some of the most commonly asked questions about fish tank filter noise.
Q: What Should a Fish Tank Filter Sound Like?
A: Ideally, your fish tank filter should be pretty much silent. However, like any form of mechanical device, you will notice a small amount of noise coming from the filter.
It’s actually the filter pump that you should hear. Most pumps emit a low, humming sound, which shouldn’t be intrusive. Basically, you should be able to watch TV or work without being disturbed by the fish tank filter.
If you have a waterfall filter system, you might also notice the soft trickling sound made by the water as it reenters the aquarium.
Most people don’t find that noise especially irritating, and the sound tends to fade unobtrusively into the background.
Q: Does a Loud Filter Bother Fish?
Although fish don’t have obvious ears, they aren’t deaf. In fact, a fish’s auditory organs are adapted to detect both airborne and waterborne sounds through the water.
Fish have sound-perception organs, including cilia (fine hairs), otoliths, bladder, and accelerometers. Fish detect low-frequency sounds pretty efficiently since those sounds travel quicker and over longer distances.
However, loud, sudden noises amplify and transfer faster in water than in air.
So, if your dog barks at the fish tank, he’s more likely to frighten the fish momentarily than if your filter constantly hums in the background.
Q: What Else Could Cause the Noise?
If it’s not the filter pump itself, the sound you’re hearing could be caused by an external pump vibrating against the surface it’s placed on.
You can usually solve that problem easily and quickly by standing the pump on a mat or piece of fabric that absorbs the vibrations.
I hope you enjoyed our guide to solving the problem of a noisy fish tank filter. If you found the article helpful, please take a moment to share it.
Every type of filter has the potential to become noisy eventually.
The usual causes of a rattling noise from your filter are defective parts, clogging of the filter and internal parts of the unit, incorrect water flow, and direct contact with a solid surface.
If you can’t fix your noisy filter by following our tips, it could be time to buy a modern replacement.
Did your fish tank filter disturb your fish? How did you fix it? Tell us in the comments box below.