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Why Does My Fish Tank Smell?

Posted by on Jan 22 2024

Whether you are a seasoned fish keeper or have just set up your first aquarium, if your fish tank smell is getting in the way of your enjoyment of it, it’s time to take action. We talk you through a few of the reasons your fish tank might smell as well as ways to help stop your fish tank from smelling.


Why Does My Aquarium Smell?

There are several reasons why your fish tank could be smelling, this includes reasons why your aquarium water is cloudy and smelly. Fish tanks have delicate ecosystems that require just the right level of care and it may also be that you are overdoing something rather than not taking the right steps to care for your fish. It is also worth noting that all fish tanks will have a slight smell due to their nature. When that turns into a strong or overpowering smell however, that is when there may be a problem with your fish tank water.

Why is My Fish Tank Making My Room Smell?

If your fish tank smell has reached the point of making your room smell, there may be an underlying problem. Below are a few reasons why your fish tank might smell.


  • Rotting food at the bottom of your tank

  • Dead fish

  • Overstocked tank leading to a buildup of fish waste

  • Rotting plants

  • A dirty fish tank filter or old, ineffective air stone

  • Gas trapped in the fish tank substrate is causing a smell


How Do I Stop My Fish Tank From Smelling?

Luckily there are a few things you can do to stop your fish tank from smelling. Regular maintenance is key to stopping your aquarium from smelling. Below are a few steps you can take to stop smelly fish tank water:



1. Inspect your fish tank for any dead fish or plants. If you have a particularly busy aquarium, dead fish could have become caught and become hidden in your tank. If you have fish that are prone to jumping in your aquarium, be sure to check the areas surrounding your fish tank as well. If the fish tank smell is related to rotting fish, the problem should clear up almost immediately.


2. Monitor how much you are feeding your fish. Overfeeding your fish can cause excess food to sink to the bottom of your fish tank and rot which can cause a whole host of problems in your fish tank. Check out our simple how often should you feed your fish guide to make sure overfeeding isn’t causing your fish tank water to smell.


3. Make sure you are only housing the right number of fish in your tank for the aquarium size. When stocking or setting up your fish tank, pay close attention to how many fish will live there. Overpopulation in a fish tank can easily lead to a build up of waste which can damage the health of your fish as well as cause cloudy-looking fish tank water and make your fish tank water smell.


4. Clean your fish tank. Keeping your fish tank clean and healthy is the biggest step towards stopping your fish tank from smelling. Take a look at our guide to how often you should clean your fish tank to avoid over-cleaning your fish tank and stop your fish tank from smelling. When cleaning your fish tank, pay attention to the aquarium filter to ensure it is not blocked with debris. A smelly fish tank may also be caused by a build-up of gases or waste in the gravel so be sure to regularly clean and ‘vacuum’ the gravel with a gravel cleaner


5. If your aquarium water is cloudy and smelly, there could be an issue with the chemical balance of your fish tank. Take a look at our guide to ‘why is my fish tank water cloudy’ to help troubleshoot your cloudy and smelly tank water problems.


Aquarium Supplies to Help Stop Your Fish Tank Smelling

CD Aquatics stock a wide range of aquatics supplies to help care for your fish tank and reduce the risk of your fish tank water smelling. Take a look at our fish tank cleaning supplies to keep your tank healthy or our general aquatics supplies for more aquarium upkeep. Alternatively, contact our team to find out more.

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