Everything You Need to Know About Cleaning a Fish Tank

cleaning a fish tank

Like any other pet, happy and healthy fish require a clean and hygienic environment to thrive in. It is a long-term commitment that includes love, care, and commitment. Cleaning fish tanks is not a one-time job. Since a fish tank is an enclosed ecosystem where your fish are swimming 24/7, it is easy for waste to build up. This can turn toxic if not removed and cleaned regularly. All fish tank objects require regular maintenance, including water filtration, testing and overall cleanliness of all components. While it might seem overwhelming at first, if you know what to do, then you will end up with a clean tank in no time. So, read on to find out more about cleaning a fish tank.

Cleaning Fish Tanks in a Few Simple Steps?

Step 1: Gather Supplies

The first step is to collect all supplies that you will require for an extensive fish tank cleaning activity. These typically include,

  • Bucket 
  • Bleach
  • A razor blade 
  •  Algae scraper
  • Water siphon or gravel vacuum
  • Glass cleaner 
  • Filter brush
  • Filter media
  • Chlorine remover
  • A clean cloth or towels 
  • Water conditioner

Depending on the size of your tank, you may use some or all these pieces of fish tank cleaning equipment. However, these are some of the handiest fish tank cleaning equipment.

Step 2: How to Clean the Water?

You don’t have to take the fish out for this process. In fact, removing fish from their everyday environment can cause undue stress. You can replace water with the help of a siphon gravel vacuum. It is essentially a 2-inch wide plastic tube attached to a siphon tube. It helps remove waste as well as water from the fish tank into a bucket. 

While changing water, keep in mind to remove only up to 30% of the water. Any more and it will imbalance the biological filter. Lastly, replace the water slowly so that the temperature does not fluctuate too much. 

Step 3: How to Clean Fish Tank Rocks and Gravel without a vacuum?

It is very easy for leftover food to settle at the bottom of your tank and leave you with dirty gravel and rocks. Removing this debris regularly, not just cleans your tank but also maintains a healthy environment. 

Since fish tank rocks and gravel are perpetually in water, algae formation is very common. Fill a clean bucket with 1 portion of chlorine bleach and 9 portions of water. Soak the rocks and gravel in this mixture for half an hour and drain them at the end of the period. You can then use a sponge or a soft brush for further cleaning. Make sure that you are wearing gloves and protect your clothes appropriately. Once the objects are clean, soak them in a solution of water and standard chlorinator three times for periods of 5 minutes. Let them dry out in the sunshine before you put them back in.

You can use white vinegar to remove that crusty layer that is usually formed as a result of excess calcium. Keep them fully submerged for a few hours, after which you can use a medium brush and clean them. Make sure that the rocks are entirely dry before setting them back in the tank. 

Here’s a video on how to clean fish tank rocks. 

Step 4: How to Clean Fish Tank Filter?

Before embarking on a fish tank filter cleaning project, find out the type of filter you have. This will determine the cleaning method that you can adopt. It is easy to find out the type of filter you have by looking at the user manual. It will also give you any specific directions that you need to follow while removing dirt from the filter. 

Filters are usually of 3 categories – mechanical, chemical or biological. 

Mechanical Filter Cleaning Process

Most mechanical filters have a pad or a sponge inside them. It is this component that requires most cleaning. 

  1. Use a few cups of the existing tank water to clean the filter’s sponge rather than fresh or distilled water. It will be less of a shock to your fish and they will not be sensitive to the change. 
  2. Once you have taken the required water from the tank in a bowl or a bucket, unplug the filter and remove it from the tank. 
  3. Wash all the dirt from the pad or the sponge using just the tank water. Make sure you keep on washing until the water running through it is clean and clear. You can also replace the sponge if you feel that it is beyond cleaning. 
  4. Once the sponge is clean you can move on to other parts of the bowl. Just make sure that you use the water from the tank. You can use a filter cleaning brush for scrubbing out dirt from the remaining filter. 
  5. The last step is to put the clean sponge back in place and fit the filter back in its original position in the fish tank. You can now turn on a clean filter.

Chemical Filter Cleaning Process

In comparison to mechanical filters, chemical filters are convenient to clean. You just must replace the carbon regularly. This can be done once every week or whenever the water turns cloudy. Like the mechanical filter cleaning process, here also you are required to follow steps 1, 2, and 4. 

Biological Filter Cleaning Process

The biological filter cleaning process is not as rigorous as cleaning a mechanical filter or a chemical filter. This is because you want to retain all that tank skimming bacteria. Just give it a quick clean using just the tank water and follow the steps listed above.

While you should always clean the fish tank filter when it gets dirty, it is important to give a gap of at least a week. This will allow enough time for the fish to calm down between 2 cleanings. Also, once you have refitted the filters back on their respective fish tanks, make sure that they are functioning correctly. You can always consult the owner’s manual in case of any discrepancies.

Step 5: How to Clean Fish Tank Glass?

 Keeping the fish tank glass can make the overall fish tank look more presentable. Since the aquariums and fish tanks are environments where you feed the fish, all components are bound to get dirty in the process. Therefore, it is important to keep them clean from all the feedings and excretions. Just put on some cleaning gloves and dip your hands right in the fish tank. 

Cleaning the glass from outside

Of course, cleaning the glass from outside is much simpler. Therefore, this is where you should begin. You can use warm water, paper towels or a soft cloth for this purpose. You can also use a little soap to remove stubborn dirt stains. However, make sure that you clean off the soap thoroughly. 

Cleaning the glass from inside

At the offset, make sure that you select a cleaning sponge that will not leave any scratches on the glass. Start by removing the fish tank cover to gain easy access. Gently slide the sponge on the inner glass to remove dirt, algae, and other sedimentation on the glass. Just keep your movements gentle and smooth. Sudden or aggressive movements can lead to water spilling from the tank. 

You can also use an algae scraper to clean your fish tank. For tough algae, you can use a pronged scraper, and for normal dirt, you can use a regular scraper. Unlike the sponge, an algae scraper is a reusable tool provided you rinse and clean it in warm water. 

How to Clean Fish Tank Glass?

Step 6: How to Clean Fish Tank Accessories?

Most of us are excited about the new fish tank decorations. However, this enthusiasm diminishes over time and the decorations are left gathering dust and algae. So, if you want to see that crystal clean look again, then it is time to undertake some cleaning projects. 

Begin by removing the decorative pieces and placing them in a clean and soap-free sink. You can use an aquarium sponge or a small soft brush to remove dirt and algae. Rinse the decorative pieces thoroughly before placing them back in the clean fish tank. The fish might seem disturbed the first few times you remove and replace the decorations. However, they will get used to this once you clean the decorations regularly.

Bleach Cleaning

Hard algae may not come off quickly. In such cases, you can use diluted bleach. 

  1. Create a bleach and water solution by mixing 4 freshwater gallons with 2 ounces of plain bleach. 
  2. Make sure that you wear appropriate clothing as bleach can discolor your clothes.
  3. Place the decorative items in this bleach bath and leave them there for some time. The soaking period depends entirely on the state of these decorations. Pieces with stubborn dirt and algae will require to be soaked for longer. However, make sure that you don’t leave them for longer than necessary, as this can lead to discoloration. 
  4. Check the decoration after about half an hour as this amount of time is enough to get rid of strong dirt and algae. 
  5. Make sure that you rinse the pieces thoroughly with water and let them dry naturally before placing them back in the clean fish tank. 

Don’t take all the decorations out for cleaning at once. Clean about half of them at a time. You can also keep 2 sets of decorations so that as you are cleaning one, you can replace the tank with the other set. 

How to Clean a Fish Tank?

The Importance of Cleaning Fish Tanks

Removal of Organic Compounds

The particulate organic matter (POM) and dissolved organic matter (DOM) are organic matter that is a natural by-product in a fish tank where fish are fed regularly. The food waste is broken down by colonies of bacteria and becomes an organic waste that needs to be removed periodically.

Regulating Nitrates

Bacteria convert ammonia into nitrite and subsequently into nitrate in a nitrogen cycle. Both nitrite, as well as ammonia, are harmful to fish. This makes it essential to have bacteria colonies to convert all the possible harmful compounds into nitrate. Further, nitrates are not as harmful to the fish and can be easily removed by changing the water regularly. 

Maintain Essential Minerals

It is highly important to maintain an optimum balance of minerals in your fish tank. If this is not done, then it can result in an osmotic shock for the fish that can ultimately kill them. Therefore, it is important to regulate the hygiene and maintenance of your fish tank without fail. 

How to Regulate Fish Tank Maintenance?

The frequency of fish tank cleaning depends on 2 important components – the size of the fish tank and the number of fish residing in it. Also, if you have a saltwater tank, then change at least 10% of the water every week. In the case of freshwater tanks, you should do a partial water change of up to 20% every 2 weeks or so. 

Logically speaking, more fish will lead to larger bio-dump. This, in turn, requires more frequent water changes. This holds for smaller tanks as well. 

Further, by carrying out small daily and weekly fish tank maintenance tasks, you can maintain a healthy tank without putting in too much effort. 

How to Maintain Fish Tank – Daily Tasks?

  • Check your fish for any abnormalities.
  • Remove the leftover food after 5 minutes of feeding the fish. Since most feedings happen twice a day, this will hardly take any time.
  • Check the specific gravity of water and its temperature.

How to Maintain Fish Tank – Weekly Tasks?

  • Conduct a brief equipment check weekly, including filters, lights, etc. Remember, this is just a quick check to look for anything faulty. You can always carry out extensive checks during regular tank cleanings.
  • Do water checks, including ammonia, nitrite, and pH levels. This can be done at a store, or you can invest in a water testing kit and do this at home. 

How to Control Algae in the Fish Tank?

Objects in a fish tank are perpetually submerged in water. Therefore, algae formation is normal and okay. While you can’t stop this, you can always control the rate at which it grows and spreads. Follow these tips to keep algae levels in check and keep your fish tank clean.

  • Test water regularly for chemical buildup. An increase in the levels of nitrate, phosphate, and iron can lead to a faster spread of algae in the fish tank. 
  • Remember not to overfeed your fish. Overfeeding can also increase the phosphate levels in the fish tank water.
  • Replace the media as soon as it becomes ineffective.
  • Also, use only high-grade media and filters. 
  • Use an algae scraper while cleaning the tank. 
  • Adding live plants in your aquarium or fish tank can also help regulate the speed at which algae spreads. Although, it is important to do your research and consult a professional before deciding on what plants you can add to your fish tank.
  • Do not keep the light on in the aquarium or the fish tank for more than 8 hours a day. Also, keep it away from direct sunlight. 
  • Lastly, change the water regularly enough to reduce the rate at which algae gets formed. It will depend on the size of the tank and the number of fish you have living in it.
  • You can also buy algae control products to keep its spread under check. 

How to Clean and Prevent White Residue Formation on the Fish Tank Glass?

Keeping the transparent fish tank glass can become a daunting task, especially if you have fish that prefer hard water. White residue is usually a result of water that has evaporated from the top of the tank. While this residue is not harmful to your fish, it can make the fish tank look dirty and shabby. 

While you can find different brands of fish safe cleaning sprays at your local pet store, there is a greener option available. Using plain white vinegar on a dry fish tank can help you clean it at a fraction of the cost. Apart from being a natural disinfectant, vinegar is effective in dissolving difficult line deposits as well. 

However, in this method, you will have to take the fish out of their tank and relocate it to another holding tank. The next step is to remove all the decorations, plants, gravel, and drain the tank completely. 

Cover the stained-glass area with vinegar and let it remain for 15 to 20 minutes. Next, use a cloth or a non-abrasive pad to scrub the glass clean. You can also use an algae scraper or a razor blade to get rid of any stubborn patches. However, make sure not to scratch the surface. 

Preventing Lime Build-up on the Fish Tank Glass

Since lime buildup is a direct result of evaporation, just keep on checking the tank’s water level. Warmer temperatures or low humidity in winters can affect the rate at which the tank water evaporates. Also, as water evaporates, it makes the remaining tank water harder. Therefore, keep in mind to replace the evaporated water with distilled water to maintain the density of minerals. 

Best Products for A Clean Fish Tank

A filter may not be enough to keep the fish tank clean. Here are our top pics among cleaning products for keeping your fish tanks clean and hygienic. 

Best Glass Cleaner

Magnetic glass cleaners are an excellent solution for those who don’t like sticking their hands in the fish tank. Keep in mind to invest in smaller ones like the Aqueon Aquarium Glass Magnets so that they reach all nooks and corners. 

However, if you are not completely comfortable using magnet glass cleaners, then the best product for you is a Ken Marine Pro-Scrapper II. it is highly durable and comes with three different blade fittings.

Check Price Here

Best Algae Grower

While selecting algae pads, it is essential to ensure that they are free from any chemicals or soap. The presence of these elements can prove to be lethal for the fish in your fish tank. 

As a water filtering device, this algae grower uses light to grow healthy algae. It also performs natural filtration and removes the most harmful and undesirable chemicals from the fish tank water. 

Check Price Here

Best Spray

The Safe & Easy Aquarium cleaner is probably the best product in the market to get rid of those stubborn stains from lime buildup. It is important to use only those cleaning products that are safe and specifically designed for fish tanks and aquariums. 

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Best Net

Nets are one of the most crucial and most ignored components of the aquarium. Using products like NetSoak can make sure that your fishnets last for longer and prevent disease transmissions. 

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Best Gravel Cleaner

A good siphon or gravel cleaner works just like a good vacuum on a dirty carpet. While it is not essential to use a siphon vacuum to clean gravel, using one can finish the job much faster. The Aqueon Siphon vacuum is an excellent product that separates dirt from gravel. The 6-foot flexible hose is perfect for cleaning fish tanks of different sizes.

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Best Filter Brush

A filter brush is an essential product for keeping your filters clean. The Uxcell filter tube cleaner brushes are excellent products for this job. They come in different compact sizes and are incredibly efficient in removing any dust or dirt from the filter water pump’s tube. They can also clean the filter’s intake stem.

Check Price Here


Aquariums and clean fish tanks give our home and living space a sense of peace and calm. However, a dirty fish tank can have the exact opposite effect on the surrounding environment. Therefore, follow the tips mentioned above to keep your fish tank clean and healthy at all times. Also, invest in good and reputed products that are free from harmful chemicals and can help you keep the fish and the tank hygienic. With regular care and maintenance, your fish tank will always look pleasing and beautiful.