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How to Clean Fish Tank Gravel the Easy Way: Detailed Guide

How to Clean Fish Tank Gravel the Easy Way: Detailed Guide

Cleaning is not the funniest part of fish keeping. Most tank keepers would love to learn how to clean fish tank gravel the easy way, without all the hassle and stressing out the fish. 

Everyone knows about regular water changes and cleaning the tank glass. However, what many people miss is cleaning the gravel. Yes, even the substrate needs regular cleaning!

I am sure this process sounds rather daunting. In the end, everything stands on the substrate, which means you have to move all the decorations beforehand, right?


What if I told you there is an easy way to clean the substrate? More than one, to be precise! Sounds tempting? It should!

If you want to know how to clean fish tank gravel the right way, you’re in the right place! I’ll share all my knowledge with you. 

Let’s get started! 

What Can I Clean Fish Gravel With?

fish aquarium

The first step to learning how to clean fish tank gravel is knowing what to clean it with. 

There are certain tools made for cleaning that can make your life easier. Yes, I am talking about the gravel vacuum. Many similar tools exist, but only the gravel vacuum can clean gravel to perfection. 

Of course, this isn’t the only solution. There are many homemade remedies that can help keep your fish tank sparklingly clean!

And as a first-aid kit, there are even some fish and other aquatic animal species that can do the job for you!

Here are several easy ways in which you can keep your substrate clean:

With a Gravel Vacuum 

The most straightforward option is to use a gravel vacuum. However, this tool can be a bit tricky to use if this is your first time.

To help you out, I’ll explain how you can use it in a few easy steps: 

Step One: Choose the Right Vacuum

The important first step might seem obvious, but I need to mention it: You need to pick the right type of vacuum for your tank and aquarium substrate type.

There are two types of gravel vacuums:

  • The siphon-style vacuums
  • The electric gravel vacuums

Siphon-style vacuums are most commonly used due to the huge variety of products available. Also, they are rather affordable, and there is a product for almost everyone’s budget! 

The biggest downside of these products is that they take some getting used to. Also, if you use them incorrectly, you can expect a lot of spillage. Finally, most models require you to drain all the water from the tank.

Electric vacuums are modern solutions that keep your tank clean without removing the water. They are (mostly) efficient and can help you clean any gunk, food leftovers, and fish waste.

However, as you might’ve guessed, electric vacuums are rather expensive. Not just that, but as they are fairly new solutions, they are far from perfect. There is a great chance you might have to modify the product you’ve bought for it to fit your needs.

As such, I would always advise using a siphon vacuum. Sure, they might not be as straightforward, but they have never let me down!

Also, large tanks might require vacuums with a longer siphon and long and wide mouth. This will help you complete the process without that much work.

Similarly, if you have lots of decorations, go for a more narrow mouth. This will help you clean the tank without ruining your plants.

Step Two: Turn off the Equipment

Before you start , you need to prepare your tank before you can clean aquarium gravel. 

This means that you should turn off all tank equipment. From filters to air pumps and heaters, nothing cannot stay turned on. Even if you only have a filter (and you should have one, as it’s considered the most essential part of the equipment), turn it off before you start working on your tank.

One of the reasons behind this is that you don’t want to risk your possibly expensive objects malfunctioning once you lower the water level, but more on that in a minute. 

More importantly, any aquarium equipment that is turned on during the cleaning process can be a safety hazard.

For example, a heater can be a fire hazard. When you lower the water level, the thermostat might end up above the surface of the water. As the room temperature is often cooler than the water temperature, this can lead to a malfunction and even a fire.

The filter might also end up above the water surface. When this happens, it will suck in air instead of water. This will result in a malfunction. 

Step Three: Lowering the Water Level

Next, you should lower the water level. This is to help you reach the substrate without too much trouble. Also, it is a necessary step if you are cleaning fish tank gravel with a siphon.

You can do this by using an ordinary clean bucket or with the help of the aquarium siphon. Use this opportunity to change the water later on. Since you should replace about 10-20% of aquarium water each week, this is a good time to complete this step, as well.

Don’t remove too much of the water! You want to keep all the beneficial bacteria inside of it. If you take more than 40% of the water, you might have to cycle it again.

If you need to make the tank glass crystal clean, now is the time to do this! Get that algae scraper and get rid of all the green stains and limescale. 

The reason behind this should be quite obvious: Anything you scrape off will fall down and end on the substrate. There is no point in cleaning the gravel before you clean anything above it. You’d just be doing everything for nothing!

Step Four: Get the Bucket!

Now it’s time to prepare the surroundings for this process. What you’ll need is a bucket and a few towels. 

Lay the towels around the aquarium so they can pick up any spillage that might occur. The end of the siphon should go into the bucket. 

I would advise you to use a new bucket and not the one you’re using for cleaning. Even traces of soap and detergent can ruin the water chemistry, making it unsuitable for your tank inhabitants.

The vacuum head should be placed inside the tank, with its top remaining outside of the water.

Step Five: It’s Vacuuming Time

Finally, it’s time to start vacuuming!

Once the vacuum head has filled with water, lift it up. It should be fully outside of the water. Wait for the water it has previously picked up to start pouring inside the bucket. The moment this happens, quickly put it back into the water.

Congratulations! You have started your siphon gravel vacuum.

If you’re using the electric vacuum, you might be able to skip this step. Most of these units are self-starting. The same goes for more advanced siphon vacuums, as well! All you need to do is push a button once or twice for the unit to start sucking in small particles and debris.

When the vacuum has started, put it onto the gravel and allow it to suck in any plant matter, fish waste, uneaten food, and any other dirt that might be found inside the substrate.

Move the vacuum back and forth, just as if you were vacuuming your own floor. This will make sure you don’t miss a spot. 

Step Six: Keep on Vacuuming

By now, the bucket should be filling up with dirty water. This is because all the dirt and debris is going through the siphon and outside of the tank. 

Keep a close eye on the water that’s running out of the hose. As long as it’s dirty, there’s more vacuuming to be done in that area. Once you notice that you have clean water pouring out, it means you can switch to a new spot.

To ensure a healthy environment for your fish, I wouldn’t advise you to clean the entire gravel at once. There is plenty of good bacteria living inside the substrate. This bacteria is essential for aquarium cleaning, as it’s controlling ammonia levels inside the tank.

As you suck in the dirt from the gravel, you are also sucking in any microorganisms that live there. If you go overboard, your fish might have a hard time adjusting to the new, overly clean environment.

Step Seven: Remove the Vacuum

Finally, once you’ve ensured your gravel is clean, it’s time to take the vacuum out of the water.

Unless you’re using the electric one, there is no need to turn it off the same way as if you were to turn off a regular vacuum cleaner. You simply take the head of the vacuum out of the water. This will do the trick.

Make sure your vacuum is positioned upward. This will keep the dirty water from reentering the tank and ensure it’s going into the bucket. 

Finally, add some new water into your tank. Don’t pour water from the bathroom or kitchen sink! Such water contains chloride which is harmful to aquatic life. Use dechlorinated or RO/DI water instead.

If you fear that you have disrupted the bacterial balance inside the water, don’t panic. All you need to do is cycle the new water before pouring it into the tank. You can do this in just 24 hours!

Without a Vacuum

While using a gravel vacuum is likely the best way to clean the substrate, there are a few other methods. Just keep in mind they might be more time consuming.

If you have large fish tank rocks, there is no need to use a vacuum. You can clean them with white vinegar instead! Just give them a good scrub and maybe use a razor blade for persistent spots. While this sounds like too much effort, it doesn’t take as much time as you’d think.

Also, you can clean the gravel by hand. All you need to do is remove about a third of the dirty gravel from the tank. Then, replace it with the clean new gravel

If you don’t have clean gravel, you can simply wash the old gravel instead. Give it a good rinse with hot water and maybe add a bit of vinegar, as well. A bleach bath might help, as well. Just remember to dilute the bleach so the gravel can remain safe for aquarium use.

Once again, keep in mind that the clean new aquarium gravel doesn’t contain good bacteria. Don’t change all of it at once.

The Clean-Up Crew

You can also keep the clean-up crew to make sure your tank is kept clean for a fairly long time. 

The clean-up crew consists of aquatic life that is known for its poop-eating habits. This includes:

These critters are scavengers that will eat anything that falls to the bottom of the tank. While they aren’t a replacement for a good vacuuming, they can do a great job of keeping your tank debris-free.

How Often Should Aquarium Gravel Be Cleaned?

zebrafish in freshwater aquarium

There is no need to go overboard with cleaning the gravel. As mentioned several times before, gravel is home to many healthy microorganisms. If you clean it too much, you’ll kill all the good bacteria that keeps the water in balance.

However, this doesn’t mean you should never clean your substrate. Even if you have the entire clean-up crew, this isn’t enough to ensure your tank is hygienic. 

A general rule is to vacuum your gravel once a month. The precise timing depends on many factors – most notably the condition of your tank.

Still, by conducting monthly cleaning, you’ll ensure the gravel is clean just as much as it should be to provide your fish with the best condition possible. 

The Bottom Line

There is no way to avoid cleaning the gravel. This task is just as important as cleaning any other part of your aquarium. 

However, just because something is a necessity doesn’t mean it has to be challenging. Using a vacuum is an easy option for anyone wondering how to clean fish tank gravel with as little effort as possible.

Of course, if you don’t want to spend money on buying a gravel vacuum, you don’t have to. There are several other methods that have proved to be just as effective – although perhaps not as straightforward.

Whichever option you choose, it’s important to regularly clean your gravel, but also to not go overboard. Too much cleaning might cause more trouble than not cleaning at all. 

Balance is the key to giving your fish the best living environment possible.