Will Cloudy Water From Sand Hurt Fish? {Best Ways To Clear It Up}

I needed to find out why cloudy water from sand dust took over my tank. Will cloudy water from sand hurt fish?

Do you also need to know how to get rid of sand dust in an aquarium?

Let’s get into tips and solutions about cloudy water, its causes and effects on fish in this article.

Will Cloudy Water From Sand Hurt Fish?

No. Adding sand to your aquarium is an excellent idea and a nice step up from artificial gravel. But, the cloudy water from the sand can hurt the fish. Although it won’t kill them, you won’t want your fish in such an environment.

That cloudy fog you see when you want to add new sand to a water-filled aquarium are tiny particles of sand and dust that need time to settle out of the water column.

Will Sand Dust Harm My Fish?

No. A bed of sand can serve a multitude of purposes in your aquarium. It can aid:

  • Food digestion in fish
  • Make cleaning more approachable

Sand dust has no harmful effect on your fish. Sand is an excellent addition to your aquarium, but cloudy water discredits the good look of the aquarium.

In most cases, the specks of dust in the aquarium can be caused by:

  • a dirty tank
  • algae

Aside from the fact that it creates a cloudy look, excess sand dust can upset the aquarium’s oxygenation.

How to Get Rid of Sand Dust in Aquarium

We would like to take a minute to help you with an idea that will get that cloudy sand dust out of your aquarium. Here is the plan:

  1. You fill a bucket with water.
  2. Add the sand.
  3. Stir it up.
  4. Pour out the cloudy water.
  5. Repeat this until the water is more apparent.

This process will extract the dust and fine particles which you reprobate. Once you extract, you may need to siphon off dust and debris from time to time.

A small tube about the size of a garden hose will work fine for siphoning. Hold this about an inch above the sand as well as the dust.

You may want to rinse the sand each time you clean the aquarium, but always ensure it’s returned to the tank at room temperature to avoid shocking your fin friends.

Will Cloudy Water Kill Fish?

No. Cloudy water, synonymously known as Bacteria Bloom, occurs 2 to 4 days after you put the fish in the tank. The cloudy water cannot harm or kill fish in as much as they aren’t gasping at the surface.

After starting an aquarium, it is not a peculiar scenario for the aquarium to become cloudy. This cloudiness results from the nitrogen-converting bacteria colonizing to oxidize ammonia and nitrites.

The appearance of cloudy water in an aquarium is not harmful to a fish. However, it is a sign of imbalance in some vital aspects of your fish tank.

It can be due to:

  1. Overfeeding your fish
  2. Leftover Food

Overfeeding your fish

This can make the water cloudy as the uneaten food is allowed to decompose. Per feeding, you should not feed more than what your fish can eat in one to three minutes.

Leftover Food

Suppose you have any bacteria or microscopic life in your aquarium. In that case, this leftover or uneaten food means they now have a source to feed on, multiplying rapidly and quickly.

When bacteria is of high level and effective in your aquarium, it can result in the creation of a cloudy effect in it.

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How To Get Rid Of Cloudy Water In Fish Tank

Let it go: The best way to get rid of the initial burst of cloudy water is to let it go. Although it seems counterintuitive, it helps to prevent the consistent occurrence of cloudiness in water.

If you let the natural cycle complete, the cloudiness will go away in a few days to a week. The fish will be fine if they are not gasping at the surface.

Cleaning the filter doesn’t affect the cloudiness in the water, but it only disrupts the few beneficial bacteria that have had a chance to get established. Letting nature take its course is the best option for you.

If you have changed your tank’s water, that can be a big reason for bacteria bloom. To get rid of this, wait for a week or two.

Why Cloudy Water Won’t Go Away?

The cloudiness of your water tank should start to gradually clear up as soon as the bacteria in the tank is reestablished. Avoid persistently changing your water or UV sterilization as it can further increase the bacteria bloom.

However, the bacteria bloom is caused by other factors like:

  • substrates
  • excess waste
  • decaying food

How To Get Rid of Cloudy Water

  1. Perform a partial water change.
  2. Use a gravel vacuum to eliminate the tiny particles floating in your tank.
  3. Purchase a bio-magnet water clarifier. These product is made to pull particles from the water column to help settle at the bottom quickly.

Partial water change is the key here, as it won’t damage the bacterial culture which has already been existing.

How Long Does It Take For Sand To Clear In Tank?

Sand is a light substance that will float around in the water. The cloudy problem after adding sand is that the sand contains some dust.

Some people report that it can take up to 7 days for the sand to settle, depending on how fine the sand is. Rinsing the sand well to take out extras is a way of making the sand settle.

Another thing to do is to give it a little bit more time. It tends to settle by a time when you leave the sand for a few days.

How To Make Sand Settle Quicker In Tank

What you can do to speed up the rate at which the sand in your aquarium settles is to perform daily water changes. Although you will lose a bit of sand this way, if you do daily water changes of about 50%, you can cut the time it takes the sand to settle in half.

Ensure you don’t agitate the water and sand too much when doing these 50% water changes daily. The gentler and smoother you can be when doing this, the better off you will be and the faster the sand will settle.

Performing daily water changes for a few days should allow the sand that has already settled to stay there, and it will remove a lot of the sand floating in the water.

What Causes Cloudy Water In Aquarium?

Generally, too much light, nutrient imbalance and poorly maintained aquariums are the number one causes of green cloudy water.

1. Too Much Light

Phytoplankton is a plant, and like most plants, it thrives very well in abundant light. The use of strong aquarium lights or keeping lights on for too long will encourage green aquarium water.

Reducing the time and amount of light that your aquarium receives is a simple and effective step that can stop green water from appearing in your aquarium. Avoid locations that can expose your aquarium to direct sunlight such as near windows and keep your curtains down.

2. Nutrient Imbalance

Using too much or too little of a nutrient could encourage green aquarium water. How so? Algae is a plant that competes with the others planted in the tank, and when a nutrient imbalance occurs, it is very possible to create conditions that favor the growth of algae, often without even realizing it.

By constantly checking your water parameters, you can notice unusual fluctuations in CO2 levels or phosphates and take preventive and corrective action.

3. Unmaintained Aquariums

Keeping a regular maintenance routine is one of the basic steps that must never be neglected. Waste and decaying fish food,(from overfeeding)will accumulate and trigger all manner of avoidable complications.

You can do the following to keep on track.:

  • Regular water changes
  • Clean your filter
  • Check your water parameters
  • Clean your gravel/substrate with a gravel vacuum
  • Remove uneaten fish food

What Causes Yellow And Brown Cloudy Water?

If you have driftwood in your aquarium, it could cause a change in the color of your water. Well, driftwood contains substances called tannins which are natural dyes.

When immersed in water, the tannins slowly leach from the wood. Malaysian driftwood, for example, turns tank water to brown. Manzanita driftwood hardly releases any color. The colors are harmless to fish.

A simple solution for this is to boil the trunk or wood before placing it in the tank. That will release most of the tannins, and you don’t have to worry about them clouding your aquarium.

Can I Add Fish to Cloudy Sand Water?

No. Your fish will not enjoy being added into a tank with cloudy water. The sandy or cloudy particles floating in the water column may cause adverse reactions to your fish such as:

  • Entering their mouths
  • Irritating their eyes
  • Impaction in their gills
  • Infections

Sensitive or stressed fish will end up feeling the effects of life in cloudy water. They can get ill faster and may ot recover. The best thing to do before placing sand in your aquarium is to thoroughly wash it off first. After a good rinse, the sand should not be as cloudy.


You are sure to know what to do when your tank appears cloudy. You need to ensure optimum living parameters for your aquarium animals and carry out the necessary maintenance routine to prevent them from any harm.


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John Brandon

John has kept fish all his life (since he was about 5). He started with keeping guppies and fell in love with fish keeping almost straight away. That was 40 odd years ago. These days John still keeps fish and currently has two large tanks where he keeps many different types of fish such as Angelfish, Neon Tetras, Goldfish, Guppies and many more.