How To Keep Fish Tanks Clean – Methods, Supplies, & More

    Learning how to keep fish tanks clean longer, as a novice or as someone that has tried and given up on fishkeeping, will make you a lot more confident and allow you to enjoy the hobby to its full potential!

    It’s easy to get discouraged when water gets cloudy, algae and grime build-ups are at an all-time high, and, worst-case scenario, fish start dying.

    Setting-up your tank, diving head-first into aquascaping, and introducing fish are the most exciting parts of getting into the fishkeeping hobby. But becoming an aquarist comes with a fair share of responsibilities.

    An aquarium is a contained environment, which means that whenever things go south (water quality drops, disease strikes, etc.), you’ll have to act quickly to fix the problems in question.

    Staying on top of your tank maintenance schedule is the best way to make sure that your fish stay healthy, your tank stays clean, and the view is always crystal-clear.

    The Best Ways To Keep Fish Tanks Clean Longer

    How to keep fish tanks clean

    Cloudy, algae-infested, or discolored tank water is one of the first signs that your tank’s water quality is dropping and that you’re either not cleaning your tank often enough, or your maintenance schedule isn’t ideal for your tank’s set-up.

    These tips will get you into an efficient tank cleaning groove, and you’ll be rewarded with clear water.

    The aesthetics alone will show you how totally worth it this hobby can be. But having healthy, active fish and eliminating the guesswork behind how to keep your fish tank clean longer are both significant perks.

    Use an appropriately-sized tank filter.

    Your aquarium’s filtering system plays a huge role in how efficiently the water gets cleaned.

    A filter that’s the right size for your tank will filter out fish waste, dead plant matter, leftover fish food, and other debris.

    Depending on your fishkeeping budget, a filter that includes mechanical, biological, and chemical filter media is preferred in any tank set-up larger than a fish-bowl.

    Clean the filtration system periodically to make sure it isn’t malfunctioning and that it’s working at its full capacity.

    Clean/change filter media regularly.

    Mechanical filter media (coils, sponges, foam pads) should be cleaned once every four weeks, as the build-up of waste can negatively impact your filtering system’s performance.

    Chemical filter media needs to be changed on a monthly basis. Activated carbon is the most popular chemical filter media fishkeepers use. It adsorbs chlorine, tannins (which color the water), and phenols (which cause unpleasant odors). It also prevents your tank water from turning yellow over time.

    Aquarium carbon can only absorb so much content until it gets oversaturated and becomes inefficient.

    Biological filter media (biofilter balls, rings, stars) are placed in a tank to give good bacteria a place to colonize and grow.

    Biological filter media may clog up with beneficial bacteria growth. But you should never throw it away. Give it a rinse using aquarium water to remove the heaviest growth. This ensures your filter continues to flow normally.

    Don’t forget to scrape algae from the interior glass using a magnetic algae scraper. These also remove biofilms, snail eggs, and other unattractive additions to your aquarium viewing glass.

    Use aquarium test kits regularly.

    A drop in water quality, or significant changes in water parameters, can be subtle enough to go unnoticed. This doesn’t mean your fish aren’t affected by these sudden changes.

    Using aquarium test kits (for freshwater or saltwater) regularly, as a weekly task in your tank cleaning routine, will help you monitor water parameters and warn you when to intervene.

    Water parameters (pH, salinity, water hardness, Mg, Ca, etc.) all fall within a certain range, so you only have to address a problem if a parameter is way off the limits that your fish are accustomed to.

    Do 20% water changes once every two weeks.

    The rule of thumb with water changes in a healthy well-established aquarium is that you should change 20% of the tank’s capacity once every two weeks.

    You can go as low as 10% or as high as 25% when doing water changes at this interval, but never try to put it off for a longer period of time, and then do a massive water change.

    An excessive water change can throw your tank’s bacterial balance off and cause havoc in this self-contained environment.

    Water changes are meant to remove nitrate surplus from the tank’s water, which is a natural component resulting from going through the nitrogen cycle.

    Remember to allow tap water at least 48 hours to stand before using it to perform a water change. A sudden influx of chlorinated water will do more harm than a typical water change can do good.

    Siphon your tank’s gravel periodically.

    Siphoning the gravel will eliminate some of the leftover food that drops to the bottom of the tank during feedings, as well as other debris that didn’t make it into the tank’s filtration system.

    You have to keep in mind that the gravel is also a breeding ground for your aquarium’s culture of nitrifying bacteria (the good kind!), so harsh gravel washing will cause a bacterial-imbalance.

    You might have cleaner gravel, but a bacterial-imbalance will make your tank get dirtier quicker and can sometimes even turn the water toxic for all of the tank’s inhabitants.

    Don’t forget to clean your tank’s lighting system.

    This is a tank cleaning task that you can carry out just when there are obvious signs of lime build-up.

    Forgetting to clean your tank’s lighting system can cause it to malfunction quicker.

    Be sure to use an aquarium-safe lime cleaner to get this task done. Some aquarists use vinegar to get rid of lime build-up. You might have to relocate fish while cleaning the tank’s light fixtures, as any residue that makes it into the water can be extremely dangerous for your pet fish.

    Clean the outside glass panels.

    Cleaning the outside glass panels might not seem like the most critical step in keeping a fish tank clean, but you’ll definitely notice a difference if done regularly.

    Dust, fingerprints, and even water droplets that fall during regular maintenance can all make an aquarium look messy.

    Never use household glass cleaners on an aquarium. The chemicals are toxic to fish and plants. Instead, use unscented cleaning vinegar or aquarium-safe glass cleaners for wiping the outside glass panels.

    Disinfect fish nets and aquascaping tools after every use.

    Fish nets and aquascaping tools can become breeding grounds for bacteria (not the good kind!), and you can unknowingly harm your pet fish by not disinfecting them after each use.

    All you need to do is keep a container of disinfectant on hand and let fish nets and other tools soak for a bit. You can air-dry them once they are disinfected.

    How To Make Fish Tanks Easier To Clean

    how to keep a fish tank clean without a filter
    Pearl gourami (Trichopodus leerii)

    Getting rid of the guesswork on how to keep aquariums clean gets even easier when you set your aquarium up for success during the initial set-up.

    There are easy precautionary steps you can take to keep your aquarium sparkling clean, even if you’re the type of fishkeeper that tends to slack off on tank cleaning duties. 

    Add live aquatic plants to your tank set-up.

    Live plants will not only improve oxygenation in your aquarium, but they will also use up excess nitrates to feed themselves.

    This means that water changes every two weeks become less of a critical necessity, especially in a heavily planted tank with a reasonable number of fish.

    You can go longer between water changes if you keep live aquatic plants in your aquarium, but you should still perform water changes regularly.

    You’ll also have slower algae growth because your plants will feed on the same nutrients that algae would need in order to grow.

    Of course, you’ll need to monitor your plants and remove dead leaves, replant uprooted seedlings, and get rid of decaying plants.

    Decomposing plant matter can turn your tank’s water toxic just as easily as rotting fish food can. Trimming back live plant growth also removes the nitrates and other pollutants they use as fertilizer.

    Here are some popular live aquatic plants you can plant to make your fish tank easier to clean:

    • Pygmy Chain Sword;
    • Rotala Rotundifolia;
    • Hornwort;
    • Java Fern;
    • Moneywort;
    • Cryptocoryne wendtii.

    Add tank-cleaning fish and critters.

    Tank-cleaners are algae-eating fish (or invertebrates) that can help you keep algae growth under control. They also do an awesome job at keeping the inside walls of your aquarium sparkling clean.

    Snails and most catfish species are well-known for their tank cleaning abilities, as they will just munch on algae continuously. They are a great alternative if you don’t want to use store-bought algae control solutions.

    You’ll need to make sure you pair your new cleaning crew with the right tank mates because snails, in particular, can often be seen as snacks for some fish species. Loaches, Betta fish, Gourami fish, and Labyrinth fish are all eager snail eaters.

    Here are some of the most efficient tank-cleaning species you can add to your tank:

    Don’t overfeed your fish.

    Overfeeding fish is not only harmful to fish themselves, but it can have a series of negative side effects that will be harder to combat than they are to prevent.

    Leftover fish food will sink to the bottom of your tank and quickly start rotting, releasing excess ammonia and nitrites into the water. A well-established culture of nitrifying bacteria can handle some occasional leftover food, but large quantities of decaying fish food will turn the water toxic.

    Overfeeding fish can also cause snail infestations, increased algae growth (which results in green tank water), and clogged-up filtering systems.

    You’re just doing yourself a disservice by overfeeding. Your pet fish only need as much food as they can finish eating during the first 1 to 2 minutes of a feeding session.

    Don’t keep the lights on 24/7.

    Having your tank lights on for 10-12 hours daily (on a diurnal schedule) is not only healthy for your pet fish, but it can also keep your tank cleaner in the long run.

    Algae will bloom freely if you were to keep the lights on 24/7, and stress levels among fish would rise as well. If you have a heavily planted tank, keeping the lights on is a must, but exposure to light for 10 hours a day will have your plants growing just fine.

    Choose the tank’s assigned location wisely.

    Setting up your tank in a location where it is exposed to too much sunlight will make it harder to clean.

    Algae-control is almost impossible to manage when the aquarium is constantly exposed to light.

    Having a tank stand in direct sunlight can also cause sudden temperature spikes (cool-downs), which can be stressful to fish that prefer a narrow water temperature range.

    Placing an aquarium right next to a heater or in a very drafty spot in your home will have the same negative impact.

    Away from constant sunlight and not anywhere near a heater/air conditioning unit is the best location for your fish tank.

    Choose less messy fish.

    If you’re unlikely to stick to a regular cleaning schedule, go for pet fish that are traditionally known to be less messy. Gravel diggers and messy eaters are the biggest offenders when it comes to fish that will cloud-up tank water quicker than others.

    Goldfish and large cichlids are notorious for digging fish waste and debris from the bottom of the tank as they dig while also making big messes with their ravenous eating style. 

    Avoid overcrowding.

    Overcrowding your tank with fish is the easiest way you can inadvertently cause your tank to get dirtier sooner. So, if you’re on a search for ideas on how to keep your fish tank clean, with a tank chock-full of fish, it’s time to start over!

    More fish equals more waste, more strain on your tank’s filtering system, more ammonia/nitrites for your tank’s culture of good bacteria to break down, etc.

    Overcrowding an aquarium with large fish or countless fish of all sizes will simply overwhelm your tank’s biological filtration capacity.

    Water quality will constantly be at a dangerously low level. 

    How To Clean Your Fish Tank Without Losing Good Bacteria

    Cleaning your fish tank following a basic maintenance routine is vital to the pet fish you’re keeping.

    But what most novice aquarists find out the hard way is that you should never deep-clean a tank!

    This might sound counter-intuitive, but unlike you would clean your home to get rid of all the bacteria, aquariums actually need bacteria to self-sustain their biological filtration system.

    If you were to remove all the nitrifying bacteria in your tank, you would basically send your aquarium into a state that’s known as “new tank syndrome”.

    You can keep fish tanks clean without without losing good bacteria by doing smaller clean-ups on a regular basis, rather than catching up on your cleaning duties all in one go.

    How Often Should You Clean A Fish Tank?

    cleaning fish tank with vinegar
    Kuhli loach (Pangio kuhlii)

    How often you should clean your fish tank is entirely subjective, as your aquarium’s set-up is rarely going to be exactly the same as another fishkeeper’s set-up.

    Cleaning frequency will depend on several factors:

    • Tank size;
    • Fish types;
    • Number of fish;
    • Planted or not;
    • Freshwater or saltwater;
    • Location/exposure to sunlight.

    Here are some timelines you can use as guidelines when scheduling your tank maintenance tasks:

    • Water changes – every 2 weeks (20%);
    • Clean filter – monthly;
    • Change/clean filter media – monthly;
    • Change biological filter media – every 3 to 6 months;
    • Siphon gravel – weekly;
    • Use test kits – weekly;
    • Clean light fixtures/exterior glass panels – monthly;
    • Clean interior glass panels – bimonthly (using an algae scrubber).

    Must-have Cleaning Supplies For Fish Tanks

    • Magnetic algae scrubber 

    Magnetic algae scrubbing pads will make cleaning your tank’s walls (inside and outside) a whole lot easier. You put one pad on the interior side of a glass panel and lock-it in with the second pad placed on the exterior side.

    Drag the algae scrubber on all four upright glass panels to get rid of algae build-up.

    • A multi-purpose utility pump 

    Larger aquariums can be harder to clean simply because you’ll need to move a large volume of water during bi-monthly water changes.

    A multi-purpose utility pump will make this task significantly easier to carry out, as you can siphon out gallons of water completely hands-free.

    • Freshwater / Saltwater nitrifying bacteria

    Adding nitrifying bacteria to a tank isn’t something you can do only when first setting up your aquarium.

    If you’re keeping large messy fish, or you plan on introducing a significant number of fish to a community tank, an additional supply of good bacteria will help the established culture of bacteria inside your tank to keep up with the extra influx of ammonia/nitrites.

    • Freshwater / Saltwater flocculants

    Flocculants are chemical coagulants designed to clump-up the smaller loose particles of waste that contribute to the murky-water-looking water inside a tank.

    As they clump together, these waste particles become easier for the aquarium’s filtering system to manage. Fishkeepers use flocculants for clear tank water.


    Every novice aquarist can keep their fish tank clean, especially once you realize that the “secret” behind a crystal-clear aquarium is just staying on top of your tank maintenance schedule.

    Alternating, gradual clean-ups of all the elements that keep your aquarium running smoothly will make it easier for you to enjoy the fishkeeping hobby. 

    Decide which tasks you can do weekly, bimonthly, monthly, or just when needed, assign them to get done on a regular basis, and you’re all set!

    Here are a few tips to make your aquarium look cleaner:

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