How to clean your aquarium in 5 simple steps

To understand why it is necessary to clean the aquarium, the importance of regular cleaning, how often it is necessary to clean it, and the acceptable parameters, we explain to you how to clean the aquarium in five simple steps.

To ensure your fish stay healthy, it’s vital you make sure you maintain optimum aquarium conditions.

This requires routine maintenance and cleaning to help maintain the delicate ecosystem in the tank.

How to clean your aquarium

The water in your aquarium can easily become harmful to your fish if it is not cleaned properly.

If you clean your aquarium properly, you will never have to remove all the water at once. In fact, by doing so, you kill any good bacteria that has built up.

If you’re a complete novice, you may find it easier to clean a small tank or bowl; this is an incorrect assumption. The larger the aquarium, the easier it will be to maintain stable water conditions.

Index Hide


  • 1 Why you need to clean the aquarium
    • 1.1 1. Adjust the nitrate cycle to keep it in low concentration
    • 1.2 2. Remove dissolved organic compounds and particulates
    • 1.3 3. To replenish essential minerals
  • 2 Regular maintenance
    • 2.1 Daily maintenance of the aquarium
    • 2.2 Weekly aquarium maintenance
  • 3 How often should you clean your aquarium?
    • 3.1 Dessert parameters
    • 3.2 Marine parameters
  • 4 How to clean your aquarium in five simple steps
    • 4.1 Phase 1 – Preparation
    • 4.3 Step 3 – Remove algae
  • 4.2 Phase 2 – Removing the water
    • 4.4 Phase 4 – Cleaning the filter
    • 4.5 Phase 5 – Water replacement
  • 5 Aquarium Cleaning FAQs
    • 5.1 How do I clean a used aquarium?
    • 5.2 How do I clean an aquarium containing eggs?
    • 5.3 Should I remove the fish?
  • 6 In summary

Why you need to clean the aquarium

There are three goals you are trying to achieve when cleaning your aquarium; these are known as the three Rs.

  • Regulate the nitrate cycle.
  • Remove dissolved organic compounds and particulates.
  • Replenish essential minerals.

1. Regulate the nitrate cycle to keep them in low concentration

The nitrate cycle is the process in which ammonia is converted by bacteria into nitrite and then into nitrate. Both ammonia and nitrite are toxic to fish and therefore having colonies of the bacteria in your aquarium is essential for converting them into nitrates.

Nitrates are much less harmful to fish and can be removed with regular water changes.

Before introducing any fish into an aquarium, the cycle should have been activated; there are several ways to activate the cycle in your aquarium. One of the best ways is to add artificial ammonia to your aquarium to start building the bacterial colony that destroys ammonia and nitrite.

2. Remove dissolved organic compounds and particulates

Organic compounds are defined by chemists as compounds of carbon and hydrogen (they can also contain other atoms as well). Examples include sugars, fatty acids, vitamins, amino acids and proteins.Organic matter is classified into dissolved organic matter (DOM) and particulate organic matter (POM).

DOM is defined as any organic material that can pass through 0.2 0 1.0 um filters, while POM will not be able to pass through.

Organic matter includes any waste produced as a natural by-product of an aquarium full of fish, which are regularly fed. Just as ammonia is broken down by colonies of bacteria, so too is food waste and other organic matter in your aquarium.

Plants in freshwater aquariums can use up some of these organics, and the rest can be controlled by regular water changes and cleanings, as we’ll discuss later in the article.

3. To replenish essential minerals

When fish are kept in water with too little, too much, or too little mineral, this can lead to osmotic stress, which in turn can lead to osmotic shock and ultimately, death.

Often when fish owners add water to their aquariums, they use water that has gone through the reverse osmosis process. This process removes most of the impurities in your tap water but also removes the essential minerals your fish need.

Therefore a specific product must be used to add these essential minerals back into the aquarium.

Regular maintenance

Before we start taking a look at techniques for cleaning your aquarium, we’ll take a look at the regular daily and weekly maintenance tasks you’ll need to undertake to ensure your aquarium stays in good condition between cleanings.

Daily maintenance of the aquarium

These daily chores only take a few minutes and make all the difference in maintaining a healthy aquarium.

  • Feed your fish twice a day and remove any uneaten food after a five-minute period (this will prevent uneaten food from breaking down and affecting water quality).
  • Do a quick check on all the fish in your tank (are they all behaving normally, with no injuries and no disease?).
  • Check the water temperature and the specific gravity of the water (by monitoring these two parameters every day, any adjustments can be quickly and easily corrected).

Weekly aquarium maintenance

  • Water controls pH, nitrate, nitrite and ammonia levels and salinity (in marine aquariums). You can have the water tested at your local store or simply buy a test kit to do at home. The kits are extremely simple to use: they are a colour-coded strip of paper, which helps you determine the levels in your aquarium.
  • A brief check on equipment, filter, lights etc. This should just be a quick check to make sure everything is working properly, the rest can be done while cleaning the aquarium.

How often should you clean your aquarium?

The amount of water you need to replace and the regularity of your water changes depend entirely on the size of your tank and the amount of fish you have in there.

As a guideline, you should aim to give your freshwater aquarium a 10-20% partial water change every 2 – 3 weeks.

For a marine aquarium, you should change 10% of the water every week for the first year, then you can follow a similar guideline for freshwater aquariums.

If you maintain your aquarium correctly, you should never have to do a complete water change, in fact: doing so will remove all the bacteria that are essential for breaking down the waste created by your fish.

The more fish you have, the greater the bio-load and the faster the water needs to be changed; the same goes for smaller aquariums, as the water becomes unstable.

During the first months of the introduction of fish, it is necessary to regularly monitor the water conditions of the aquarium.

You will begin to get an idea of ​​how often your tank should be cleaned by keeping a record of all parameters.

The parameters depend entirely on the species you are keeping, but you can use the following parameters as guidelines.

Remember that different species have more specific requirements, so you should always research the fish, coral or invertebrates you are keeping in your tank to verify acceptable parameters.

Sweet parameters

Temperature22 – 27  or C22 – 27  or C0.5 –  24o C
pH6.5 – 7.57.5 – 8.46.5 – 7.5
Alkalinity (Carbonate Hardness)4 – 8 KPH10 – 18 KH4 – 8 KPH
General hardness4 – 12GH12 – 20GH4 – 12GH

Marine parameters

ParameterFOWLR AquariumReef aquariumCoral reef aquarium
Temperature22 – 27  or C22 – 25  o C27  or c
pH8.1 – 8.48.1 – 8.48.0 – 8.5
Alkalinity8 – 12 dKH8 – 12 dKH6 – 8 dKH
specific gravity1.020 – 1.0251.023 – 1.0251.025
Ammonia (NH3)AbsentAbsentClose to zero
Nitrites (NO2)AbsentAbsentClose to zero
Nitrates – Nitrogen (NO3)<30ppm<1.0ppm0.25ppm
Phosphates (PO4)<1.0ppm<0.2ppm0.13ppm
Soccer350 – 450ppm350 – 450ppm380 – 420ppm
Magnesium1150 – 1350ppm1250 – 1350ppm1300ppm
Iodine0.04 – 0.10ppm0.06 – 0.10ppm0.06ppm
Strontium4 – 10ppm8 – 14ppm8 – 10ppm

How to clean your aquarium in five easy steps

  1. Preparation
  2. Water removal
  3. Algae removal
  4. Filter cleaning
  5. Water replacement

Phase 1 – Preparation

Gather all the tools you need, listed below.

Tools you will need to clean

  • Gravel vacuum cleaner
  • Algae scraper/pad (magnetic cleaner recommended)
  • Large bucket (make sure this is only used for cleaning the aquarium so that household chemicals do not enter the aquarium)
  • New filter (optional)
  • Used clean towel/cloth
  • Replacement water (quantity and type depends on how much you need to replace and if you have a saltwater or freshwater aquarium)
  • Water test kit
  • Generator set and heater (marine aquarium)
  • Salinity probe (marine aquarium)
  • Most aquariums are too heavy to move, so you’ll need a siphon that allows you to draw water out of the tank and a bucket that allows you to carry replacement water into the tank.

Unplug all electrical elements in your aquarium: heater, filter and any pumps.

Remove any large decorations or ornaments.

Make sure you do this slowly and in a way that you don’t kick up any debris at the bottom of the aquarium.

If you have artificial plants, you can remove them if they need a cleaning, but never remove live plants, this will disturb root growth.

Stage 2 – Removing the water

You will need to replace approximately 10-20% of your aquarium water every 2-3 weeks.

Use a siphon gravel vacuum, with a hose attached, to clean the gravel and remove the water.

You should suck up small amounts of gravel using the siphon; the waste will then be drawn through the hose into the bucket along with some of the water, and the gravel will fall back into place.

Use your thumb to clamp the end of the pipe to slow the siphoning process and make sure no gravel gets into the pipe.

Some siphons come with a built-in regulator to control the flow of water, some even come with longer hoses so that the water can be carried directly to the sink (if it’s not needed to flush other fixtures).

This step not only gets rid of the water, but it also cleans the gravel, abundantly removing the waste that has fallen into the substrate.

Step 3 – Remove algae

The easiest way to clean aquarium glass is to use magnetic algae cleaner.

A magnetic algae cleaner consists of two magnets with a soft felt lining. You place one magnet inside the aquarium and fit the other together outside the aquarium.

It then drags the outer magnet around the aquarium glass, and the inner magnet follows and gently removes most of the algae.

If you have an acrylic aquarium, make sure you choose a cleaner that won’t scratch the surface.

If you want to clean any of the other larger decorations removed (from step two), you can do so in the bucket of siphoned water, using a clean, soft-bristled toothbrush.

Never use soap or other cleaning products, it can be deadly for your fish.

You may also want to consider having a group of cleaner fish, which will eat some algae in the tank.

Step 4 – Cleaning the filter

Depending on the type and quality of filter you use, you will need to clean and sometimes change the holder in your water filter.

The most common type of filter is a sponge filter. To clean this, you need to remove it and rinse it in the bucket of water removed from the aquarium.

Never use the filter under tap water, as it removes the accumulated beneficial bacteria needed by the aquarium.

Any other filters that act as mechanical filters, such as a sponge (ceramic rings, fibre, etc.) should be rinsed and replaced as quickly as possible, to avoid losing bacterial colonies.

If your filter contains carbon, ammonia absorbents or ion exchange resins, it will need to be replaced every two weeks, because it will no longer be able to absorb the materials.

You should also clean the rest of the filter, including the hose. Use a filter brush for this.

Step 5 – Water replacement

Your aquarium now needs to be filled with water again.

The type of water you add depends on whether you have a saltwater or freshwater aquarium.

Water preparation for freshwater aquarium

If you have time to prepare the water ahead of time, leave the tap water out for 24 hours before cleaning the tank to evaporate any chlorine in the water.

You will need to use a water conditioner to remove all heavy metals, chlorine and toxins which are harmful to fish.

Preparing the water in advance, allows the water to reach room temperature as well.

Preparation of water for the marine aquarium

You will need to be more precise with water changes in saltwater aquariums. It is necessary to observe three parameters: salinity, temperature and pH.

For reef aquariums, you will need reverse osmosis water and/or deionized water. You can buy it at your local store or you can buy a system that produces water of that type. You should use this water for any type of saltwater aquarium.

You should only use tap water if the water in your area is excellent, and even then, tap water should only be used for fish-only aquariums. If tap water must be used, have it tested for total dissolved solids; this reading should be zero, but anything less than 10 is fine.

You will need to dechlorinate the water and then add a salt mixture. There are many options available, so make sure you choose a quality brand. Follow the instructions according to the product you choose.

Most salt mixes will need to be added to the hot, swirling water. You can do this with a headstock and a heater.

You should leave the water like this overnight before adding it to the aquarium, to allow the salt to completely dissolve.

Always make sure the temperature and salinity of the water are as similar as possible before putting it back in the tub; this avoids sudden changes in your aquarium.

Check the water parameters in your aquarium after a couple of hours and also check that the water is not cloudy.

Finally, you can clean the outside of the aquarium simply by using a specific aquarium cleaner and a cloth.

Aquarium cleaning FAQ

How do I clean a used aquarium?

The aquarium should be completely empty before cleaning. You will need salt, vinegar and some gentle scrubbing pads.

The vinegar and salt will remove hard water stains and fishy odours. Make sure you rinse the aquarium thoroughly before adding water.

After thoroughly cleaning the aquarium, fill it with water to check for leaks. If you find leaks, you can use sealant.

How do I clean an aquarium containing eggs?

If the eggs were laid in gravel, you can proceed with your usual cleaning, but avoid gravel until the eggs hatch and the fry are swimming.

If they have been placed elsewhere, just avoid that area when cleaning and do not expose them to air.

Most eggs hatch within a week, so they shouldn’t affect your cleaning schedule.

Should I remove the fish?

Unless you have a very small tank or tank, you shouldn’t remove the fish while you’re doing the water change.

Fish do not like to be disturbed and removing them can cause stress. If absolutely necessary, keep them in the same water as their aquarium.

Ideally, you should do much more frequent partial water changes even with a small tank or bowl.

summing up

Cleaning your aquarium shouldn’t be a strenuous task. The key to keeping your aquarium clean is regular and ongoing maintenance.

Partial water changes are one of the most important aspects of ensuring your fish stay healthy and happy.

Performing partial water changes ensures that colonies of bacteria, which are essential to your aquarium, are not displaced or damaged.

It’s not a difficult task. Simply follow the steps we have provided for you!

Elizabeth Canales is fond of marine life since childhood and got an aquarium as a gift from her father on her 6th birthday. Since then she started to take care of Coralia (her goldfish). Her love for fish made receive her B.S. in Marine Biology from the University of Washington and DVM from Delaware State University.

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