Why is my Aquarium Sand Floating?

It can be frustrating if your aquarium sand keeps floating to the top of your tank. In this article, I will explain why aquarium sand floats, and how to prevent it in the future.

Why is my aquarium sand floating?

The main reason your aquarium sand is floating is because there are dust particles. Your aquarium sand might also float because it has air bubbles.

Lastly, it is also common for aquarium sand to float if there is a disturbance in the water.

Dust particles

Dust particles attached to the sand is the main substance that will float. This is caused by the dust particles being very small and light. Since they aren’t heavy enough, they will frequently float to the top of the aquarium. You can avoid this by washing the sand before you put it in your aquarium. You can see how in my video below.

Air bubbles

There is also a chance that some of your sand grains have air bubbles trapped inside of them. This can cause the pieces to float to the top. This is very common in new aquariums. Luckily, grains of sand that have air bubbles will soon get water logged and should sink to the bottom in a couple days.

If they refuse to go down after a day or two, you should try pushing them under the water with your hand. If they refuse to sink, you might just have to scoop the floating pieces out of your aquarium.

Disturbance in water

It is also common for sand to float to the top of an aquarium if there is a disturbance in your tank. This could be caused by your fish or turtle making a sudden movement that causes the sand to be pushed around. It can also be caused by a filter or air pump being pointed at the water.

Luckily, most of the time the sand that floats after a disturbance in the water will fall back down to the water soon.

Now that you know what causes sand to float to the top of an aquarium, let’s discuss some of the ways you can prevent it.


I know this sounds counterproductive, but most of the time, your sand will float back to the bottom of your tank in a day or two. This is almost always the case if you have a new aquarium.

It will take a couple days for the sand to get water logged, which can result in some of the smaller pieces floating to the top in the beginning. If it is annoying you, it is fine to scoop out the floating pieces with a net.

If your sand doesn’t go back to the bottom after a couple days, or more sand starts to congregate at the top of the aquarium, you might need to try one of the methods below.

There is also a chance that you put too much sand in at once. If you have a 75 gallon tank, you should check out my guide on how much sand do you need for a 75 gallon tank.

How to stop aquarium sand from floating?

The best ways to stop your aquarium sand from floating is to clean the sand beforehand, invest in a power filter, and perform regular water changes.

Clean sand beforehand

No matter what type of sand you put in your aquarium, it is mandatory that you thoroughly clean the sand. This will help remove all of the small dust particles that frequently float. This will also help prevent a cloudy tank.

Start by running water through the sand. At first, the water will probably become a milky color as it collects all of the dust. However, if you keep adding new water, the water should slowly start to clear up. Once the water is clear, the sand is ready to go into the aquarium.

I suggest that you put the sand in the aquarium first, and then put the water in after. When pouring the water into the aquarium, try to do it slowly so that it doesn’t disrupt the sand too much.

If you already have your aquarium filled with water, it’s fine to add sand second. However, I suggest putting the sand in a large cup or bowl, and then put the bowl at the bottom of the aquarium and then flip it over.

Power filter

A filter can also help prevent sand from floating to the top. Powerful can suck in the small sand particles before they float to the top. A filter will also help keep your aquarium water clean and keep your pets healthy.

Regular water changes

Regular water changes can also help prevent sand from floating to the top of your aquarium. If you have a turtle tank, I suggest performing a water change at least every other week. For fish, you should do a water change at least every two to three weeks.

When you do a water change, remove around 20% of the water from your tank, and replace it with fresh water. If you are using tap water, make sure to add a water conditioner.

Air pumps

While this is more of a preventative measure, you should make sure that your air pump is not pointing at the sand in your aquarium.

If the problem persists, you might want to switch out aquarium sand with river rocks.


I hope this article gave you more insight into why aquarium sand floats. Most of the time, the sand will sink back down to the bottom of the tank after a day or two. However, if the problem persists, you should invest in a filter and perform regular water changes.

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