How Often Do You Clean A Fish Tank? Here’s Your Maintenance Guide.

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How Often Do You Clean a Fish Tank

Most pet fish hobbyist ask “How often do you clean a fish tank?” Ideally, you should clean your tank weekly. This is the ideal frequency to ensure that the aquarium is always in perfect condition.

Being a specialist in ornamental fish, through several conversations with different hobbyists, I realized that the frequency of maintenance in aquariums is still a controversial and confusing topic.

I decided to write this article to help clarify your main doubts about this topic. At first, it may seem complex, but on the contrary, it is something simple to do.

How To Know When To Change The Water

Theoretically speaking, when we clean our tanks weekly, we shouldn’t have problems like poor water quality or fluctuations in parameters like pH.

By performing maintenance regularly, we do not give the water quality a chance to degrade.

But of course, the ideal frequency of water change depends on several factors. We can cite important factors such as:

  • Aquarium population: The relationship between the tank volume and the number of animals;
  • Filtration system: We must always correctly size the filtration. When we have a low number of biological media, environmental pollution will occur faster.
  • Aquarium volume: Small aquariums, because they contain a little volume of water, are doomed to an abrupt degradation of water quality.

The best way for you to establish the ideal amount of maintenance is to perform multiple tests on your tank. From the results of these tests, you will know when your water is showing a sign of decay.

Tests for pH, ammonia, etc. should be conducted 2-3 times a week. This is the ideal frequency to keep us up to date with what is happening with our water.

So, with these results in hand, we can perform appropriate maintenance at the first sign of change, quickly correcting and adjusting the environment.

How Often Do You Clean A Fish Tank

As already stated, you should do your maintenance weekly, but this is not a fixed rule. Also, this only concerns cleaning and changing the water of the display.

In addition to this so-called more superficial maintenance, we must carry out more in-depth maintenance monthly, which consists of the total cleaning of the glass walls, filters, hoses, decorations, and everything else.

How To Do Basic Maintenance

Basic maintenance is simple and quick to perform. You can even establish a routine, increasing your efficiency and speed with the weekly maintenance of your aquarium.

To carry out the process correctly you should just perform a water change along with the general cleaning of the aquarium and especially the substrate.

Basic Equipment

To perform good maintenance, there is some equipment available in aquarium stores that are ideal to assist us in this process.

  • Siphon: Acts like the broom in our homes. It is usually composed of a hose with an open end. This open end is used to vacuum the substrate, removing the dirt;
  • Buckets: Buckets help us in different ways, such as putting the water we take from the aquarium and treating the new water.
  • Cloths: Cleaning cloths are vital for drying wet areas. To clean the outside of the aquarium, we can use microfiber cloths;
  • Glass scrapers: They may seem superfluous, but they help a lot in cleaning the inside of the tank windows;
  • Cleaning sponges: Essential for removing small dirt from glass and decorations. It is preferable to use a non-toxic and soft sponge.

Basic Cleaning

This is the first step you will take in maintenance. Prune the plants, remove the yellowed leaves, and scrape small spots of algae on the glass.

All the dirt removed will be decanted, and then it will be removed by vacuuming.

Water Changes

The most important part to know here is that the new water that will enter the aquarium must have the same standards of temperature, pH, and hardness as the water that we remove.

Otherwise, it can shock the fish, causing illness and even death.

  • If the aquarium is always in good condition, with weekly maintenance, and always stable, removing 30 to 50% of the water is appropriate.
  • In the case of aquarists who only perform monthly maintenance, I would recommend 50 to 75% water change.

Many are scared when I say this, but as long as the water that comes out is the same as the water that comes in, the more water to be changed, the better it is for the system.

A water conditioner is an essential item in any hobbyist’s pantry, and should always be used during water changes.

Substrate Cleaning

To clean the substrate properly, we use the siphon. Through it, we can access difficult and hidden areas, while it sucks up all the dirt it raises.

At the same time, we can insert it directly into the substrate, sucking up all the dirt that is trapped there. This procedure is called substrate aspiration or siphoning.

When we’re siphoning, it’s worth lifting the decorations present in the tank, so that we can prevent food and animal feces from being trapped there.

Deep Cleaning

Once a month, to guarantee the correct and stable functioning of the system, we must carry out in-depth maintenance of our tanks.


Never disassemble the aquarium or use chemical products such as soap or bleach to clean your tank.

At this stage, in addition to changing the water and cleaning the substrate, we must:

  • Clean the filters: Open the filter and remove and rinse the media and change what is necessary (such as activated carbon). Remember to always use the water taken from the aquarium to clean the different parts of the filtration system.
  • The internal part of the glasses: The best thing is to use a scraper specialized for aquariums. These cleaners usually come with a blade attached, which removes anything impregnated in the submerged part of the tank.
  • Outside of the windows: I usually use a little rubbing alcohol and a microfiber cloth.
  • Cleaning the decorations: Remove them from the aquarium and clean them with a soft brush using the water from the aquarium itself. During this process, we can remove small pieces of unwanted algae and fungi.

Preventing Problems During Maintenance

In the various aquarium stores I worked, it was common for aquarists to claim illness or loss of fish after maintenance or extensive water changes.

The reasons for this to occur are varied but always related to some basic maintenance errors. As long as we reinsert water into the tank with similar parameters as the existing one, we shouldn’t have any problems.

Change The Right Amount Of Water

When we have an aquarium in bad water conditions, most of the time the pH is very low. As a result, ammonia is building up in the water and is toxic to fish.

When performing a water change of less than 50%, the aquarium water continues to have a high ammonia content, but the pH has probably become basic or alkaline, increasing the ammonia toxicity and killing the fish.

Pro Tip

Perform ammonia and pH tests before and after performing the water change.

Osmotic Shock

An osmotic shock is causing a breakdown of the balance in the animal’s body. The main cause of this disease is when the animal is subjected to sudden environmental changes.

In practical terms, this occurs when you perform a water change and putting in “fresh” water with different characteristics from the one removed. For example, the aquarium water was hot and you put in cold water.

Pro Tip

Always measure tap water, making the necessary corrections in a separate bucket before introducing it to the aquarium.

Water Conditioner

The use of a good quality water conditioner is essential to offer our fish water with perfect quality standards.

If we don’t use conditioners, we can kill all the inhabitants of our aquarium due to heavy metal, chlorine, or chloramine poisoning.

Beware! Some poor-quality conditioners may release an excess of ammonia into the water, caused by the reduction of chlorinated compounds. Therefore, always use conditioners from well-known companies and high-performance products.

Pro Tip

The items we use to clean the aquarium should never be used for another purpose. Likewise, we must not expose them to any other kind of products or substances.

Also, if we keep our sponges and brushes always dry, clean, and stored, we avoid different types of contamination that can be passed on to the aquarium envirnonment.

Irregular Maintenance

The use of non-aquarium-specific products is a major cause of post-maintenance deaths. Another common occurrence is the dismantling of the aquarium and washing the different parts under the faucet.

Prevention Tips

We should never use chemical products to wash the aquarium. Many of the common cleaners create residues which will most likely poison the fish.

When we dismantle the aquarium, we destabilize the colony of beneficial bacteria that lives inside. The same principle applies to using water directly from the tap to wash filters and decorations.

We should only use the water taken from the aquarium itself to clean the different parts. And items like substrates and heavy decorations should never be taken out.

Final Notes

Knowing when to proceed with maintenance is simple. We can take a more conservative stance and perform small weekly maintenance work. Or else we carry out different tests over the days, changing the water at the slightest sign of instability.

Keeping the aquarium in impeccable condition and the water always at the highest quality is the best way to keep our fish free from diseases and problems.

How is your aquarium maintenance routine? How about adopting the techniques taught here and making your work more efficient, being done in less time with less effort?


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