How to Clean a Fish Tank

How to Clean a Fish Tank

Anthony Barnes

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A clean fish tank is really important as it not only looks nice but creates a good environment for your fish as well.

It is known that over time, nitrates build up and can make your tank begin to look cloudy.

Also, if you don’t clean your fish tank enough, you may begin to get a build up of algae, which doesn’t look good.

Even if you have a filter on your fish tank (see also ‘Best 50 Gallon Fish Tank‘), occasionally it is important to handwash your fish tank.

In this article, we will go through each step on how to clean your fish tank (see also ‘Best Fish Tanks‘). 

Tips For Cleaning Your Fish Tank

If you are removing your fish from the tank, be careful as possible. Also, try to handle as little as possible.

This is because you want to cause as little stress to your fish as possible.

However, it is possible to clean your tank with your fish still in the tank with you. 

Ideally, you don’t want to replace all the water in your tank.

You want to keep some as if you remove all the water then you will get rid of any positive bacteria in the water.

You will also reset your nitrogen cycle, which could also kill your fish. Partial water changes are better if possible. 

Some people may wonder if you can use soap to clean your tank. Never use any kind of soap when cleaning your fish tank.

The soap could kill your fish due to all the chemicals within them.

Even if you remove them from the tank, some particles may remain and could harm your fish. 

How To Clean Your Fish Tank

How To Clean Your Fish Tank

Getting Started

Step 1 

Begin by cleaning your own arms, hands, and elbows to make sure they are as clean as they can be.

Then take out your fish, water and any decorative plants that look dirty or need to be replaced. 

Step 2 

Once your fish have been removed, you can unplug any lights, heaters, or filters that you have for your tank.

Also close any values, to make sure nothing overflows. 

Step 3 

Any fake decoration that looks dirty can be cleaned in hot water with a toothbrush and then left to air dry, while you work on the tank. 

Removing Algae

Step 4

Start on the sides of the fish tank. Try to scrape off any algae that has formed on the sides of the tank.

If your tank is made with acrylic, then use a plastic scraper. If it is made with glass, then you can use a metal scraper. 

Step 5 

Once the algae has been removed, you can scrub and clean the sides using hot water. 

Time To Clean The Gravel

Step 6 

Once all the sides of the tank are spotless, then you can turn your attention to the gravel. By using a siphon, you can vacuum any dirt off the gravel.

By careful with the vacuum, as you don’t want to remove any more than 50% of the water while you are cleaning.

Also, be careful not to suck any of your fish up as well. 

By keeping 50% of the water, you also get to keep any positive bacteria that has been created in your tank already. 

Step 7 

To clean your filter, rinse it gently or put it in a bucket of wastewater.

Do not clean your filter in tap water, as the chlorine in the water will kill any good bacteria in your filter.

Your filter doesn’t have to be spotless, but it’s good to replace your filter media every month. 

Refill The Tank

Step 8 

Once everything is clean, you can start to put rocks, plants and any other decorations you had back into your tank.

Step 9 

You can now refill your tank with some new water.

However, the water that you add, you must make sure that any chlorine has been removed.

This can be done by using a treatment. You may notice some of the plants or decorations move once you add the water.

Just reposition them once all the water has been added.

Step 10 

Plug back in your heaters, filters, lights, and pumps. Remember to open any valves that you had closed to clean the tank.  

Step 11 

Watch the tank for a few minutes, just to make sure that everyone is switched back on and working properly. 

Step 12 

Finally wash your hands and arms. 


It is a task that many of us put off, however you should clean your fish tank when you start to notice the water becoming cloudy or algae forming on the sides.

We hope you have enjoyed this article, and now know the right and safe way to clean your fish tank.

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By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age