How to Clean Fish Aquarium Rocks?

-- By Carol

Regular cleaning is a huge part of owning and maintaining an aquarium.

You need to even clean your fish aquarium rocks since they can be covered with decaying fish and plant matter.

Algae also cover the surface of aquarium rocks if they aren’t properly and regularly cleaned.

All of this debris will eventually convert into bacteria that will harm your fish.

So, here’s how you can clean your fish aquarium rocks and keep your fish healthy.

Table of Contents

How to Clean Fish Aquarium Rocks

Aquarium rocks are usually divided into three categories – gravel, decorative rocks, and live rocks.

Let’s see how you can keep each of these types of aquarium rocks clean.

Cleaning Aquarium Gravel

Occasionally removing the waste and debris lodged into your aquarium gravel will create a better habitat for your fish.

Whether you have a small aquarium with just one fish or a large one with a variety of fish, you can easily clean your aquarium gravel at home.

Let’s look at how you can clean the gravel substrate of small aquariums.

Washing Gravel in Small Aquariums

It is relatively easy to clean the gravel placed in smaller fish aquariums.

The first step is to remove your fish from the aquarium. If you have a single small fish – such as a Betta or a Goldfish – in your aquarium, it is quite easy to remove it from the aquarium to clean the gravel.
Fill a spotless and clean glass container, similar in size to your aquarium, with non-chlorinated water. Use a fish net or even a drinking glass to gently remove your fish from their aquarium into the container. In case you don’t have a fishnet, you can use the techniques covered in this article.
Next, you need to remove the accessories or decorative plants from your aquarium. Unhook your aquarium’s water filter and remove any decorative rocks and fish toys present in your aquarium. Set them all aside. Your aquarium should now be filled with only water and gravel.
Now it’s time to rinse your aquarium gravel with treated water. To do that, gently pour out the aquarium water through a sieve. Place the sieve that has collected the aquarium gravel under a steady stream of lukewarm water. Make sure to thoroughly stir the sieve a little to dislodge and wash away all the debris and grime. Keep at it until the water running through the sieve is clear and clean.
Return the now cleaned gravel onto the floor of your aquarium. Make sure to evenly spread the clean gravel over the bottom of your fish aquarium.
You can now reset your aquarium. Reattach your aquarium filter and return all the decorative items to your aquarium. Refill the aquarium with non-chlorinated water. When everything is in its correct position, gently submerge your fish with its container into the aquarium. This will prevent you from entirely disrupting the water flow and allow your fish to freely swim away in your aquarium.

Pro Tip: If your fish species has specific water requirements, such as particular water temperatures or specific pH levels, then make sure to take that into account.

Now, let’s look at how to clean gravel placed in large fish aquariums.

Washing Gravel in Large Tanks

Washing the gravel placed in large aquariums is a little more complicated than doing so in smaller aquariums.

Here’s how you can clean the gravel in your large fish aquarium.

Don’t remove any of your fish as cleaning the gravel in a large aquarium will take some time. Temporarily relocating your fish for a significant amount of time will be stressful for them. It’s also counterintuitive and unnecessary to remove them since you will use a gravel siphon to clean your large aquarium gravel.
Position a plastic bucket on the floor next to your aquarium. Make sure to place it a level lower than the aquarium to allow gravity to work its magic

Pro Tip: Make sure that you don’t use a regular household bucket that you use for your household chores. It might have leftover chemicals or soap residue from previous cleaning jobs. These chemicals and soaps will harm your fish. Instead, use a clean bucket that you use only for your fish aquarium maintenance.

Now, it’s time to place the gravel siphon in your aquarium. Place the cylindrical end of the gravel siphon in your aquarium. Make sure that the opening is resting right at the bottom of your gravel substrate.
Next, you need to guide the other end of your gravel siphon tube over the edge of your aquarium. Hold it in your hand right over the plastic bucket.
Then, suck on the tube of the gravel siphon to generate negative pressure. Instantly, place the end of the tube into the waiting plastic bucket. As soon as you suck on the tube, the dirty water from your fish aquarium will flow through it into the bucket. Make sure to be vigilant when sucking on the tube; otherwise, you might end up with a mouthful of aquarium water.

Pro Tip: If you are not comfortable sucking on the siphon tube, invest in a siphon that comes with special priming balls. Such a siphon will automatically start the siphoning process for you. You can get it from your local pet store.

The cylindrical opening of the siphon will effectively remove the debris stuck to your aquarium gravel. While the water flows into the siphon, simply press down the submerged end into the gravel substrate.
Move the siphon in circular movements from one end of the aquarium to the other end – it works just like vacuuming does. You should be able to see grime and algae particles being lifted off the gravel. If you don’t, simply push the suction opening deeper into the gravel.

The suction might lift some small gravel pieces up in the process. If that happens, simply dislodge the gravel pieces from the tube and carry on.

Also, make sure that you don’t disturb or bump into your fish while moving the siphon around your aquarium.

Make sure that you don’t drain more than 25% of your aquarium water in one go. Doing so might upset the balance of beneficial bacteria in your aquarium. Additionally, your fish are still in the aquarium, and they need plenty of water while you are cleaning the gravel.
Once you have successfully vacuumed the gravel substrate of your aquarium, remove the siphon and set it aside. Wash the gravel siphon by running it under warm to hot water. Next, you need to discard the dirty water from the bucket. Simply pour it down your sink.
Finally, you need to refill your tank to its regular level with non-chlorinated water. Make sure that your newly added aquarium water meets the special requirements of your fish.

These gravel-cleaning methods will also eradicate the smell that aquarium gravel covered in algae might give off.

Now that you know how to clean your aquarium gravel, let’s look at some gravel cleaning and maintenance tips.

Aquarium Gravel Maintenance Tips

Apart from washing your aquarium gravel to keep it clean, you need to take certain steps to maintain it as well.

Let’s look at some steps that will help you keep your aquarium gravel clean.

Make sure to change your aquarium filter as per the manufacturer’s instructions. The prompt and correct water-filter change will prevent your aquarium gravel from amassing additional dirt.

Pro Tip: Run your old and new aquarium filters together for a few days so that your fish can adjust to the new filter.

Clean your aquarium gravel after every two weeks. Cleaning your aquarium gravel every other week will ensure the wellbeing of your fish and maintain the environment of your aquarium. Cleaning more often than the designated time will only remove beneficial bacteria from your aquarium substrate.
Make sure to not use harsh commercial cleaners to clean your gravel since most of these solutions are harmless to fish. Always rinse your aquarium gravel with plain, non-chlorinated water. If your aquarium gravel is too dirty to be cleaned via this method, simply buy new gravel for your aquarium.

Decorative Aquarium Rocks

As for the decorative rocks in your aquarium, scrub them clean with a scrubber or an algae scraper every week during your regular water changes.

This way, you won’t have to deal with a lot of amassed and decaying fish and plant matter.

Here’s how you can clean your decorative rocks:

Use an algae scraper to gently wipe the surface of your aquarium rocks. (You can clean them in the tank if they are too large. For the smaller rocks, simply pick them up and clean them.)
Swish your aquarium rocks in the dirty aquarium water that you will remove during the water change. Make sure that you don’t wash them in tap water as that will only kill the good bacteria.

Pro Tip: If your aquarium’s decorative rocks are exceptionally dirty and you haven’t cleaned them in a few weeks, don’t clean them all in one go. Clean them gradually in three weeks; remove about one-third of the scum or algae with each water change.

Live Aquarium Rocks

You should not clean your live rocks – corals – unless there’s a serious issue in your saltwater aquarium.

So, instead of scrubbing your live rocks to remove algae from their surface, you should set up a sustainable aquarium environment for them.

To achieve a sustainable aquarium environment for live rocks, you need proper lighting, filtration, steady pH levels, and fish species that munch on algae.

In such an environment, your live rocks will receive natural, biological cleaning that won’t harm them.

However, if you must clean live rocks in your fish aquarium, you need to remove them from the aquarium.

Then, gently scrub them with a soft-bristle brush. After cleaning the live rocks, soak them in saltwater.

Let the rocks remain submerged in saltwater for a period of two to three days.

In the meantime, make sure to properly aerate your aquarium water with an air stone.

Then, rinse your live rocks with salt water and place them back in your aquarium.

Why It’s Important to Clean Fish aquarium Rocks

Leftover fish food, fish fecal matter, and decaying plant matter can all settle and amass on the gravel substrate of your aquarium.

All these things will make your aquarium gravel grimy.

If left untreated, it might produce unhealthy bacteria that will eventually harm your fish.

The same is the case with decorative and live rocks that you might place in your fish aquarium.

Don’t Clean Out the Beneficial Bacteria!

It’s not crucial to wash your aquarium rocks every time you clean your aquarium.

It can actually be harmful to the beneficial bacteria living on your aquarium substrate.

Also, make sure that you don’t deep-clean your aquarium rocks to remove every single piece of dirt from their surface.

This will only kill the beneficial bacteria living on them.

Unnecessary cleaning will also disturb the roots of your aquarium plants and remove vital nutrients from them.

Deep-cleaning and unnecessary thorough scrubbing of aquarium rocks with soaps, disinfectants, bleach, etc., will do more harm than good.

Only remove unsightly gunk such as slime, algae, and fish and plant waste from your aquarium rocks.

In Conclusion

Aquarium rocks need to be cleaned occasionally to prevent decaying plant and fish matter from amassing on them.

Such debris can contaminate your aquarium habitat and end up harming your fish.

You can use the methods mentioned above to keep your aquarium rocks clean.

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