Why Is My Fish Tank Cloudy After 1 Day?

While setting up a new aquarium, it is pretty common to have cloudy water. But it does not always mean it’s in a bad situation. This is one of the most common questions from a new hobbyist, why is my fish tank cloudy after one day? How to fix it?

Cloudy fish tank can happen for many reasons. Amongst them, it can be an unbalanced pH level, bacterial bloom or it can also be dirty gravel residue. The good news is, most of the time, you can fix it by yourself.

You will get the detailed discussion in this article.

Why Is My Fish Tank Cloudy After 1 Day
Why Is My Fish Tank Cloudy After 1 Day

Reasons Why My Fish Tank becoming Cloudy After 1 Day

There is no one reason for this to happen. Here are some of the common reasons why your tank became cloudy. You have to observe closely to determine which one happened in your tank.

Incorrect pH Level

The water condition of a fish tank is very specific. If the condition is not correct then the problem occurs.

If the pH level is high than usual and if the water is not conditioned then it can become cloudy. It happens when you use tap water directly to the fish tank.

Bacterial Bloom

Bacterial bloom in the tank can turn it milky. Bacterial bloom means when new bacteria start to reproduce rapidly.

When a tank is being set up for the first time, it starts fresh. There is no biological cycle in it. But then you put some old tank water or a used filter in it, and the biological cycle starts to change. Hence, this cloudiness in the water.

Algae Growth

Excessive growth of algae can also turn the water cloudy. There are many reasons for excessive algae growth which. You will find more about this a little further.  

But when the water becomes cloudy for this reason, the color of this cloud is greenish.

Gravel Residue

While setting up the fish tank, the gravels need to be thoroughly cleaned. Because it has so much dust and sand in it than you can see.

If the gravel is dirty, it can make the water cloudy with its dirt very soon. That is why it is another less important but common reason for cloudy tank water.

What does Water Color Indicate?

The color of the cloud indicates different things as per the color. So, an aquarist needs to understand what that color means.

White or Gray Cloud

This kind of cloud may appear because of the gravel residue or bacterial bloom.  You already know why this happens from earlier discussion.

It can also happen if you increase the population of fish in your tank. More fish means more chemical reactions. Which eventually creates more bacteria and thus the cloud.

Brown or Yellowish Cloud

A Brown or yellow color cloud appears in your tank when there is an organic substance called tannic acid is present in the tank.

Tannin is produced from tannic acid. It is found in the driftwood or various plant you have put into the tank for décor purposes.

Greenish Cloud

A greenish cloud will appear when there is an algae bloom inside the tank. Apparently, algae are not harmful, but if it starts to increase constantly, they can destroy the oxygen balance in the tank.

This situation happens when there is excessive sunlight enters into the aquarium. Light nutrients help algae to grow rapidly.

Is It Harmful to the Fish?

It depends on many factors. Sometimes it is harmful and sometimes it is not.

For example, tannin which creates yellow clouds is not harmful to fish. On the other hand, the green and grayish cloud can be harmful when it goes to an extreme level.

White and gray cloud is not harmful if it is made of dust or bacterial bloom. But it can harm the fish if it is created because of any chemical reaction.

Algae bloom is not harmful to the fish at first. But if you allow it to grow rapidly, it will take most of the oxygen out of the tank. 

So, you have to make sure what is the cause of the discoloration of the water before taking any preventive measures.

How can I Fix the Cloudy Water Problem in Fish Tank?

Most of the time the tank water gets cloudy for natural reasons. In those cases, you do not have to do anything to clear it up.

Because in the cycling process it would be clear by itself soon enough. But first, make sure to do these steps so you can void most of the problems.

Wash the Tank

When you first buy the tank from the pet store, there can be so many dirty elements in it. Those can easily turn the water cloudy.

Make sure to wash the aquarium thoroughly before setting the aquarium up. It will save you from the hustle of cloudy water.

Wash the Gravel

The things you already read about the tank are also true for the gravel. In fact, gravels hold more dirt than the tank itself.

Thoroughly wash the gravel before putting it into the tank. Take the gravel into a bucket and wash it with a hose shower. Rinse it thoroughly until it gets completely clean.

Use Suitable Water for Fish Tank

While setting up a tank for fish, you cannot put simple tap water into it. There are many things you need to consider before putting the water.

Maintaining well-conditioned water with the correct pH is important here. It will also help prevent cloudy water.

Put the Tank in a Suitable Place

Put your tank in a comparatively darker area of the house. Because most fish thrive in that kind of light. A little bit of sunlight will not do any harm.

But constant sunlight in the tank will provide nutrition for the algae and it will bloom. We already know what algae bloom means for the water condition.

Do not Put Excessive Chemicals

Do not get fooled by seeing all those chemical commercials which claim to make the water healthier. All chemical has their own consequences.

Know fully how those react with others. Sometimes it’s also the cause of making the water cloudy. 



There is a lot to know when it comes to being an aquarist. Because there is a lot of biochemical reaction present in it. Especially when the cycle starts. Because that is an empty slate for the micro-organisms to grow.

So, if the water is cloudy after the first day, do not panic. There can be so many reasons and it may not be so serious. Find out the reason as mentioned above and solve the problem.

Related Posts:

Arif H Fahim

Welcome to PetFishTank! My name is Arif. I make an effort to publish educational articles using my many years of expertise as a fish owner.

Recent Posts

Мега Сайт Площадка