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How Often Should I Clean My Aquarium?

How often to clean aquarium

There are many factors responsible for how often an aquarium should be cleaned. These factors include, but are not limited to, how many fish are in the aquarium, how often you feed, and aquarium's light intensity and duration. There are also several stages in cleaning an aquarium; glass cleaning, water changes, gravel vacuuming, and filter and equipment cleaning. Not all of these stages have to be done at the same time. Some can or should be done daily, like cleaning the glass, others only have to be done periodically depending on the above factors.

In this article, I’ll discuss each stage of cleaning your fish tank and how often it should be performed based on the above factors. By the end, you will have a good idea of how often it is necessary to clean the filter cartridges, vacuum the gravel, perform water changes, and other cleaning tasks.

Why do Aquariums Need Cleaning?

Aquariums become dirty from waste build-up, toxic levels of nutrients, and excess algae. Fish excrete organic waste which ends up in the gravel and filter pads. Some of this waste breaks down into nitrates and phosphates which become toxic at high levels. Algae grows in the aquarium when there are high nutrient levels and high lighting.

Glass, décor, and equipment cleaning is necessary to remove algae. Gravel vacuuming and filter pad changes are necessary to remove waste. Water changes, chemical, and biological filtration are necessary to reduce elevated nutrient levels.

When to Clean the Aquarium Glass

clean aquarium glass

The glass or acrylic panes are often the first to become dirtied. Algae can grow quickly on the glass within hours or days. Algae accumulates on the glass from elevated nutrients and high lighting. Direct sunlight can cause algae to grow on your glass very quickly.

glass aquarium cleaning

Keeping the viewing panes clean is an important component of enjoying your aquarium. By using a magnet glass cleaner, you can wipe down the front pain of glass or acrylic as needed.

If you notice algae building up on your glass within a couple days, you should consider either decreasing your light intensity or duration, and lowering your nutrient levels.

On a weekly basis, you should clean the algae from the tank corners. This is a more delicate job as you don’t want to damage the silicone. This article details how to clean your aquarium glass.

Changing Aquarium Water

The same nutrients from fish waste that algae absorb in order to grow (nitrates and phosphates) can also build up to toxic levels in the aquarium which can cause poisoning in fish and coral.

Replacing a percentage of your aquarium’s water with new, clean water is the quickest way to reduce nitrates and phosphates. Partial water changes between 10% and 30% should be performed between once a week and once every few weeks, depending on how fast your nutrients build.

Nitrates and phosphates are more toxic to corals than fish. Check out these articles on the ideal water parameters for freshwater and saltwater aquariums.

The rate at which nutrients build up depends on several factors. The first is how many organisms are producing waste in your aquarium. The more fish you have, the faster nutrients build. The second factor is the amount of chemical filtration. Nitrate and phosphate adsorbing resins can keep these nutrient levels down in between water changes. The third factor is biological filtration. Plants, macroalgae, and anaerobic bacteria can permanently keep nitrates and phosphates low.

Water changes should still be performed even if your nitrates and phosphates are 0 ppm. There are other chemicals that can build up in the aquarium, including fertilizers and additives. If you have a reef aquarium, water changes need to be done to replace calcium, magnesium, and trace elements as they are used by corals. If you have a freshwater planted aquarium, water changes should be performed to reset fertilizer levels so they don’t build up.

Vacuuming the Aquarium Gravel

aquarium gravel vacuuming

Detritus and organic waste build up in the aquarium substrate easily. Some of it falls to the bottom before it can be picked up by the filtration. If you have a heavily planted tank with a soil substrate, vacuuming the gravel is not recommended. It's better to let waste decompose in the substrate.

In reef and other freshwater aquariums, vacuuming the gravel when you perform water changes is the best way to remove detritus and waste before it breaks down into phosphates and nitrates.

Aquarium Filter Cleaning

clean aquarium filter

Most filters have three types of filtration, physical, chemical, and biological. Each type needs to be cleaned differently and at different times.

Cleaning The Aquarium Filter Sponges, Socks, and Pads

Physical filtration is the sponges, socks, or pads that remove solid waste particles. Heavy, coarse sponges can be cleaned out, but thin, fine polishing pads should be replaced altogether. Physical filtration needs to be cleaned or replaced weekly or depending on how fast they clog from waste build up. The more fish you have, the faster the filtration clogs and the slower your filter performs.

Replacing The Chemical Filtration

aquarium gfo filtration phosphate reduction

Chemical filtration media includes resins and adsorbents that are placed in the filter to adsorb unwanted elements like nitrates and phosphates. Chemical filtration media should be replaced according to the label and does not need to be rinsed regularly. granular ferric oxide for phosphate reduction

Another way to determine how often to replace chemical filtration is to test the aquarium water for the chemical your trying to remove before you add the media. Then test again every week. You should notice the levels decrease at first, then after some time begin to increase again. When they start to climb back up to undesirable levels, it's time to replace the media.

Maintaining Aquarium Biological Filtration

aquarium biological filtration

Biological filtration comes in two forms. The first is the habitat in which beneficial bacteria lives. This habitat takes the form of porous material like ceramic or live rock. This material is usually placed near the end of the filtration process and should never be cleaned or rinsed in order to avoid removing any beneficial bacteria. If you must rinse your biological filtration because it is clogged up, do it in old aquarium water during a water change. Chlorinated water will kill beneficial bacteria.

The second form of biological filtration is plants and macroalgae. These lifeforms are efficient at absorbing nutrients and turning them into living tissue which can be easily trimmed and removed. Plants are best kept in the main display, while macroalgae, in reef aquariums, can be placed in a refugium or in the main display tank.

Algae scrubbers are also a great way to remove excess nutrients. Algae scrubbers are a separate apparatus from the main filtration that runs water and high lighting over a bed of algae which grows by absorbing nutrients.

Equipment Cleaning

Cleaning your equipment comes down to polishing and wiping down the outside of your heaters, lights, and the outside of your filters as they become dirtied with algae, hard water stains, or salt creep. A quick wipe down once a week keeps this build-up from compromising your equipment’s performance down the road, and prevents from having to uninstall, clean, and re-install equipment later on.

Cleaning Aquarium Decorations

Ideally, decorations such as driftwood, rocks, or plastic decorations can be cleaned within the aquarium. If you keep your nutrients and lighting at the right levels, algae growth will be minor enough to clean the decorations without having to remove them from the tank.

Sometimes, the build up on the decorations becomes too much and the whole piece must be deep cleaned. The best way to do this is to soak it in a solution for several days.

It is possible to use a 1:10 bleach to water solution. This will guarantee the removal of all living organisms, algae, hard water stains, and any other build up. When soaking anything in bleach that will go back into the aquarium, it is crucial to perform a second and third soak with just tap or RODI water and a double dose of a de-chlorinator such as Seachem Prime.

A safer alternative to bleach is to use a 1:4 white vinegar to water solution. Soak for 24 hours and rinse in dechlorinated tap or RODI water.

You only need to deep clean decorations when they become an eyesore for you. It's a matter of personal taste.

Scheduling Your Aquarium Maintenance

Keeping a consistent maintenance schedule goes a long way to keeping your tank pristine. Every tank is different and aquariums change over time. Your schedule may change as well, but giving yourself time to look over the details keeps you from missing problems that can grow to unmanageable conditions over time.

It doesn’t have to be complicated either. Some people benefit from an aquarium log or even an app. Personally, I use google tasks to remind me to add fertilizers bi-weekly, test and change water weekly, and clean filters monthly.


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