Easy Step-by-Step Guide on How to Clean a Fish Tank Safely

Regular maintenance and cleaning of your fish tank is essential for good fish health and keeping a beautiful aquarium.

Learn more about the importance of keeping your aquarium clean and read our step-by-step guide on how to clean a fish tank efficiently now!

Importance of Cleaning Your Fish Tank

Fish tank with a variety of fishes and live plants

Aquarists sometimes ask the question – why is my fish tank cloudy, or why are there worms in my tank?

The lack of regular tank maintenance can lead to a build-up of harmful compounds like ammonia, nitrite, and nitrate. This may result in tank cloudiness or the appearance of white worms and fuzzy subtances in your substrate.

By performing routine cleaning, you can control the level of these compounds inside the water, keeping your tank clean and your fishes healthy.

How Often Do You Need to Clean Your Fish Tank

The frequency of cleaning depends on a range of variable such as the

  • size of your tank,
  • number of fishes in the tank
  • type of filtration system used,
  • location of your tank, and
  • your feeding habits.

How to Clean a Fish Tank

How to Clean a Fish Tank (Steps)


  • Algae scraper
  • Bleach
  • Bucket 
  • Water siphon
  • Aquarium-safe glass cleaner
  • Piece of cloth


Step 1: Remove algae from the glass

Use an algae pad or scraper to scrub the interior of the tank. For larger fish tanks, PetNPat states that you can consider using an algae scraper with a long handle to help you reach deeper into the tank.

To ensure that the surfaces are thoroughly cleaned, you can use a razor blade (for glass tanks) or plastic blade (for acrylic fish tanks) to remove any remaining stubborn algae residue.

Step 2: Clean the decorative pieces in the tank

After cleaning the glass, remove all the decorations, rocks, and artificial plants and clean them using the algae scraper.

If you’re facing difficulty with removing the algae, you can soak the decorations in bleach for about 15 minutes. Once done, wash off any additional grime and leave the pieces to dry completely before placing them back in the tank.

Never use soap to clean the decorations as it’s difficult to completely rinse off; the traces of soap left on these items can harm your fishes.

Step 3: Clean the gravel

Use the siphon to vacuum the fish waste and other debris in the tank. A siphon is used as it’s able to suck up waste without removing the gravel

Attach a clean mesh stocking to the end of your siphon to prevent your fishes from getting vacuumed. You’ll also need to make sure that the mesh is large enough to allow the waste to enter.

Step 4: Turn off the equipment in the tank

Turn off any equipment like water heaters or filters in the tank before removing the water. The equipment isn’t designed to operate outside of water, and leaving them switched on may potentially cause them damage.

Step 5: Replace the water in the tank

Fill a bucket until it contains about 10 – 15% of the tank’s old water and pour it away. Alternatively, My Plumbing Professionals recommends using the old water to water your plants or wash your car tyres.

Thereafter, refill the tank with fresh, clean water. Turn on the equipment once you’ve finished replacing the water.

How to ensure the consistency of pH level and temperature of the water

 Let the clean water sit in a bucket for 1 day before adding it to the tank
This is to dechlorinate and stabilise the pH level of the water. Water containing chlorine and sharp changes in the pH level can be fatal to your fishes.

 Use a thermometer to measure the temperature of the clean water
This ensures that the temperature of the clean water matches the temperature of the water inside the tank.

This is important as fluctuations in the temperature can be detrimental to the health of your fishes.

Step 6: Clean the exterior of the tank

With the interior of the tank spick and span, it’s time to focus on the tank exterior.

Using an aquarium-safe glass cleaner, clean the exterior and wipe the surface with a damp cloth after you’re done.

Step 7: Clean the filter

Once you’re done cleaning the tank, wait for about 2 weeks before cleaning the water filter. Cleaning the filter too soon can kill the good bacteria that you’ve nurtured in the filter media.

These bacteria break down waste and prevent the accumulation of toxic ammonia, resulting in a clean, healthy aquarium. 

The method used to clean your tank filter depends on the type of filter you’re using. If you’re unsure, take a photo of your filter and bring it to a pet store to get expert advice.

How to Maintain the Cleanliness of Your Fish Tank

Fish tank with fishes and live plants
 Remove uneaten fish food from the tank
After you’ve fed your fishes, remove any uneaten food from the tank as soon as possible. This prevents the food from breaking down which can affect the quality of the water.

 Add live aquatic plants
Live plants can boost oxygen levels in your aquarium and compete with algae for nutrients, limiting their growth.

 Introduce algae eaters to your aquarium
You can also consider introducing specific fish species or aquatic animals that feed on algae to help maintain the cleanliness of your tank.

Some examples of these creatures include fire red shrimp, zebra snails, albino rainbow sharks, and golden algae eaters.

It’s important that you add animals that are compatible with your existing fishes to ensure a peaceful community tank.

Frequently Asked Questions About Cleaning a Fish Tank

Fish tank filled with aquatic plants

Do I need to remove my fishes from the tank during cleaning?

No, you don’t have to remove your fishes during the cleaning.

There’ll be plenty of water for them to swim in since you won’t be draining the tank completely.

On top of that, catching the fishes can stress them out.

If you absolutely need to, leave them in a bowl containing the same water from the tank.

How do I clean a fish tank with eggs in it?

 If the eggs were laid on the gravel
You’ll have put off cleaning it until after the eggs have hatched and the fry are swimming.

 If the eggs were laid on the glass or decorations
Proceed to clean as usual. However, you should avoid exposing the eggs to air by ensuring that the water level doesn’t fall below where they’re located.

Keeping Your Fish Tank Clean

After learning how to clean a fish tank, it’s important to maintain the cleanliness of your aquarium. Keep your fishes healthy by applying the tips provided!


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