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How to Clean Rocks in Fish Tank

how to clean rocks in fish tank

Having a fish tank in your home also means the challenge of maintaining it every day. In fact, every owner must accept that cleaning plays a big part in the maintenance process of an aquarium. Keeping the fish tank includes cleaning every part of the aquarium’s ecosystem, including the bottom’s rocks. This aquarium accessory tends to be the destination of fish waste, uneaten foods, gunks, and other forms of dirt that can harm the fish if left unattended.

But how to clean rocks in fish tank? Cleaning the rock does not require heavy scrubbing but a regular schedule to prevent the accumulation of dirt. Meaning, regularly removing the waste and debris will be beneficial in creating a healthy environment for the fish. This article will be dealing how to clean the rocks of a fish tank regardless of size. Whether it’s big or small, we will provide some detailed information on cleaning this aquarium accessory.


How to Clean Aquarium Rocks in a Small Fish Tank

When it comes to cleaning rocks in a small fish tank, you need to first remove the fish before cleaning the rocks. You can use a container similar to the size of your aquarium to serve as a temporary place for the fish. Gently remove the fish not to stress the animal during the transfer. Then, you can remove all the accessories in the tank, including all the decorations. You can also unhook the water filter leaving only the water and the rocks for the actual cleaning process.

The next step is to rinse the fish tank rock with treated water. You can pour the water from your fish tank using a colander. Put the colander under a stream of lukewarm water and stir it to loosen or remove debris and other forms of dirt. You can repeat the process until such time that the water coming off the rocks is clear and clean.

Once the rock is clean, you can put it back at the bottom of the fish tank and spread it evenly. You can also return the decorations and reinstall the filter. Then, you can refill the fish tank with non-chlorinated water while also checking on the usual water requirement, such as the pH rating, among others. Once everything is in order, you can now return the fish to the aquarium.

How to Clean Rocks for an Aquarium with Large Tanks

how to clean rocks for an aquarium

When it comes to cleaning rocks in a larger aquarium, you do not need to remove the fish away from the aquarium. Instead, you can use a gravel siphon, a special cleaning tool that is useful in cleaning larger tanks. You will also need a new bucket which will be used specifically in maintaining the fish tank. You can put this bucket at the lower level of the fish tank so that the gravity can help cleans the rocks.

Then you can place the siphon’s cylinder end and make sure that the opening is resting at the bottom of the rocks. You will also need to guide the other end of the siphon’s tubing to the bucket below. You can start sucking the tube to create negative pressure and immediately placing the end to the waiting bucket. Doing this action will let the dirty fish tank water flow through the tubing to the bucket.

You can use the cylinder and the pressure it created to remove debris in the rocks. Once the water flows freely, you can press the open and submerged end of the tubing to the rocks. You can press the mouth of the siphon down to the rocks with a circling motion to remove all the debris. When doing this action, you should see dirt and debris out of the rock and straight to the bucket. But make sure to avoid the fish as much as possible by doing it slowly and with a little bit of caution.

As a reminder, you will only need to drain 25 percent of the water and not more than that. This action is not to upset the good bacteria’s balance in the aquarium. After cleaning the debris in the rocks, you can throw away the dirty water on the bucket. You can also clean the siphon with hot water. After cleaning, you can refill your aquarium with non-chlorinated water but taking into consideration the pH requirement.

How to Clean Aquarium Rocks of Algae

If you are dealing with algae in your aquarium rocks, then the cleaning process will be different. You will need to remove the rocks away from the aquarium in a container with running water. Then to remove the algae, you can scrub them using a toothbrush or a sponge. You can clean all the cracks, crevices, and other parts of the rock.

The next step is to submerge the rock in the container with hot water. You can add ½ cup of bleach per one gallon of water. You can soak the rocks in the bleah water solution for 10 to 20 minutes to remove the algae from the rocks altogether. You can do some finishing touches by taking the rocks out of the solution and brushing them manually to remove the algae altogether.

Once you finish brushing, you will need to rinse the rocks thoroughly before returning them to the bottom of the fish tank. Ensure that the bleach solution will be removed by adequately rinsing the rock before returning it to the aquarium. This action will help make the fish safe and prevent contamination once you return the rocks to the fish tank.


Learning how to clean rocks in fish thank is essential, especially if you are still new to having an aquarium and taking care of the fish. Having an aquarium in your home is special and rewarding, but it also comes with the responsibility of maintaining and taking care of the fish. As an aquarium owner, learning all these skills is necessary to keep the aquarium environment healthy always.

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