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Why the Fish Tank Water is Cloudy? Causes and Fixeses

Why the Fish Tank Water is Cloudy? Well, this can be a wide area of concern for you if you are a fish owner and dealing with continuous cloudy water in your tank, even after trying cleaning it many times.

There can be many reasons behind the constant occurrence of this phenomenon.

Cloudy aquarium water can be caused due to significant issues like gravel residue, dissolution of various constituents, bacteria build-up, algae formation, etc. But don’t worry, you can get rid of all these wastes by cleaning your gravel and adding a strong filter to your fish tank.

Why the Fish Tank Water is Cloudy ?

So, are you wondering, why is the water cloudy in my fish tank? Well, this can be a major and valid concern to you if you are a fish owner. Dealing with dirty aquarium water is not at all an option to settle with.

So, do you know the actual reason behind its occurrence? Well, the cause can be many. Here are a few of them.

  • Dissolved constituents in your tank water

One of the main reasons behind fish tank water is cloudy can be the dissolved constituents in your aquarium. A higher level of dissolved elements like silicates, phosphates, or other heavy metals can be the real villain.

If you find that even regular cleaning does not leave any effect on removing the cloudiness of the fish tank water, you can opt for testing the water once. You will most likely find that the pH level of the water is too high, which is primarily causing this issue.

  • Residue leached out of the gravel

If you are thinking, how to stop cloudy fish tank water, you must first check on the gravel residue.

The water in your fish tank can become clouded in an hour if residues keep coming out of the gravel. If you haven’t cleaned your tank’s gravel substrate properly, it will very likely release residues in the clean water, making the water cloudy again.

  • Green water

Green water can be one of the many reasons behind why is my fish tank water cloudy green. Your tank water, turning green-colored, means it is highly accumulated with green algae.

However, there are many other reasons, which can form green water in your fish tank. Here are a few of them; have a look.

  • Excessive nutrients

The presence of an excess amount of nutrients in your tank water like phosphates and nitrates can support algae growth.

So, regularly changing the tank water can serve temporary relief to your aquarium, but algae growth will not stop until you reduce the sources of such nutrients.

  • Too much light

Too much light exposure in your tank can act as a suitable environment for algae growth. Hence, placing the aquarium under direct sun and exposing it to too much sunlight for too long can enhance algae growth in your tank, leading to the formation of green water.

  • Bacterial growth

Another possible reason behind why is my fish tank water cloudy green can be due to bacterial growth in your tank. In case you are using a new tank, it will go through a complete break-in cycle.

It might take several weeks or months to develop beneficial bacterial colonies that remove wastes from the water. However, with time, the cloudiness tends to get resolved by itself.

Decaying plants or food wastes stuck at the bottom of the water can also cause milky water or non-beneficial bacteria growth in the tank.

How to get rid of cloudy water in a fish tank?

Since now you know the main causes behind cloudy water in your tank, your next concern might be how to get rid of cloudy water in fish tanks. Well, to keep the water of your tank clear and fresh, free from any clouds, you have to put some effort into it.

  • Clean up your gravel

As we said earlier, gravel residue can be one of the main reasons behind cloudy water in your tank.

However, you can easily get rid of it if you clean your tank’s gravel substrate properly. While cleaning the tank’s water regularly, you need to consider rinsing the gravel with clean running water as well.

  • Remove all dissolved constituents

Even if you have cleaned the gravel thoroughly, you can still face cloudy or unclear tank water problems. Well, the reason behind this cloudiness is not only gravel residue.

The dissolved constituents in the tank water can be a major reason behind it. So, gravel cleaning alone is not enough here.

You have to pay attention to the water elements. The dissolved constituents can cause a higher pH level in the water. So, to control the pH, you can add a bit of a tap water conditioner or some pH buffer in the water.

In many regions, these constituents can come from tap water. So, in such cases, you can consider adding RO water to the tank. You can either buy the water from a fish store or buy an RO unit of your own.

  • Control bacteria build-up in the tank

Bacteria build-up is another primary reason that can cause cloudy water in your fish tank. Bacterial blossom can occur in your tank when a new biological filter system starts maturing.

However, you can improve the growth of beneficial bacteria in the biological filter as they’ll help in the cleaning process of the aquarium properly.

Also, you can vacuum the tank thoroughly to remove all the fish wastes or leftover food portions. It is thus always recommended to give your fish only that much amount of food, which they can consume in a few minutes.

It will help you prevent bacteria accumulation developed from the residues of uneaten food.

  • Always keep your filter turned on

Are you wondering why my fish tank water is cloudy? Well, then why don’t you equip a filter to your tank? Filters play an integral role in cleaning aquarium water.

At the same time, it helps you get rid of water clouding in your tank. But in case you switch off your filter overnight, it can trigger bacterial build-up in your tank. And this can also be the reason why did my fish tank got cloudy overnight.

Thus, your aquarium filter must be running 24×7. It will help keep the tank water clean all the time and influence the growth of beneficial bacteria.

  • Get rid of algae build-up

Since algae build-up causes cloudy green water in your tank, you need to get rid of it at the earliest. Unfortunately, algae are very stubborn, and it can give you hard times to remove algae effectively out of your tank.

So, how to get rid of cloudy fish tank water? Well, here are some remedies to eliminate algae accumulation from your tank.

  • Bright lights can be the main reason behind algae build-up in your fish tank. So, you must control it by reducing an excessive amount of light exposure to the tank. For example, you can consider moving the tank away from direct sunlight. Also, you can reduce the hours your tank lights are on.

As algae feel the lack of light, they will automatically start dying, making the filter system easier to remove them.

  • Phosphates are another reason that influences the growth of algae in tanks. So, how to get rid of cloudy fish tank water if there is too much phosphate?

Well, to reduce phosphate from your aquarium, you need to clean the tank thoroughly. Also, it is essential to trim away dead plants regularly as they can cause phosphate build-up in the tank.

Moreover, it is better to vacuum the substrate of your tank from time to time to remove dead plants, uneaten food, etc., and prevent phosphate accumulation.

  • Besides, nitrates act as algae fertilizers in your fish tank. If the level of nitrate rises in your tank, you need to act on it immediately. So, what to do? Add a filter that can effectively extract biological wastes from your fish tank. Also, a good water flow rate is essential to control nitrate production in your tank.

How to stop cloudy fish tank water?

Only knowing how to get rid of cloudy fish tank water is not enough to solve the problem. So, to get rid of it permanently, you have to follow a few hacks. Here are some tips for maintaining cloud-free water in your fish tank.

  • Avoid overcrowding in the tank

Are you still wondering why my aquarium water is cloudy? Well, too much of a crowd in your tank can ruin the water quality and induce waste build-up.

Also, over-stocking fish in your tank can come up with various troubles. Too many fish in one place can cause territorial issues, which can be a significant reason for their stress.

Also, it can invoke the spreading of various fish diseases in the tank. Besides, overcrowding in a tank can cause too much overload on the filtration unit, leading to bacteria blooming in the tank.

Therefore, you must buy only one or two fish for a medium-range or a small tank, or consider purchasing a larger tank if you plan to add more variety and number of fish.

  • Skip overfeeding

Overfeeding is neither a good idea for your fish’ health nor suitable for your tank. It can adversely affect the health of your fish.

Also, the wastes they create by not eating the whole food will get stocked at the bottom of the tank, causing bacterial bloom and aquarium clouding.

Thus, it is always recommended to give your fish the amount of food they can eat within 2-3 minutes. Avoiding overfeeding will keep both the fish and the tank healthier.

  • Seed the fish tank

To prevent water clouding in your tank, you can adopt the idea of seeding the aquarium. If you have a new tank setup, you can avoid cloudy water through this process.

Seeding of your aquarium involves transferring some substrate or décors from a mature tank to a newer one.

It helps in the growth of some nitrifying bacteria, which is essential to speed up the break-in period of the new tank. Also, it effectively reduces the likelihood of having cloudy tank water.

  • Consider adding some activated carbon media to the filter

Activated carbon has a significant benefit in cleansing and nourishing dirty water. Thus, most of the water filters use activated carbon as cartridges.

This carbon-based method can also be an effective idea for your cloudy fish tank. Adding activated carbon media to your aquarium filter can help your tank remove tannins from the water that causes yellowish and brownish stains.

What makes the fish tank water cloudy and yellowish?

Well, it may be pretty rare for your tank water to turn cloudy and yellow simultaneously, but it can happen. So, if you think, why does the fish tank water turn cloudy and yellow, then here are your answers.

One of the main reasons your water tank turns yellow or brownish is the use of tank décors. Many aquarists use bogwood or driftwood in the tank as décor.

These woods give a very natural look to the tank and allow a few plant species to grow on them. However, these woods contain tannins that can leach into the water.

These tannins tend to lower the pH balance and turn the tank water cloudy, more like the color of tea. So, if you have a fish species that prefer black water, these brownish or yellow hues in the tank water will not cause a problem. But it can make your tank look dirty.

So, in such a case, if your fish tank water is cloudy how to fix it? Well, don’t worry, we have some solutions for you. You can prevent the occurrence of yellowish cloudy water by soaking the driftwood or bogwood in a bucket full of normal water for a few days before adding it to the tank.

Also, you can add an activated carbon media filter to your tank to solve this problem, as the activated carbon will absorb the released tannins.

Why is my fish tank water cloudy green?

The water in your fish tank tends to get greenish and cloudy when uncontrollable algae growth occurs in the water.

Thus, to remove the greenish cloud from your tank water, you need to work on removing the algae from your tank.

So, now that you know why does the fish tank water gets cloudy and green, all you can do is follow the steps we discussed above and get rid of algae from your tank.

Why my fish tank water is cloudy white?

Why is my fish tank water cloudy white? Well, the color of the dirty tank water can differ due to many reasons. While you have a bit of a cloudy yellowish tone in your tank, your friend might experience greenish cloudiness in their aquarium.

Every color that the cloudy tank water displays signify its reason of occurrence. In fact, at times, the water in your tank can also turn white or slightly greyish, instead of yellow or brown color.

So, what is the reason for such whitish cloudy tank water? Well, the primary reason behind it is probably the residue build-up in your gravel substrate.

If there is some dirt, dust, or debris stuck in the gravel, it will cause the water to turn white or slightly greyish. However, you can quickly get rid of it by thoroughly washing the gravel substrate with clean running water.

Why is the new fish tank water cloudy?

Does your brand-new fish tank have cloudy water? Then it’s pretty obvious to wonder; my fish tank water is cloudy what should I do. It is undoubtedly a major concern for you, as you are just a beginner and barely know how to deal with it.

So, if you are thinking, why is the aquarium water cloudy in the new tank, let us tell you there are many reasons for that. So, knowing the reason behind it can help you to a great extent.

A newly setup tank works as a blank biological slate. In a new aquarium setup, there are no other forms of life. It usually takes time for microscopic organisms to proliferate in a new fish tank.

So, for a new tank, there are lesser chances for the growth of nitrifying bacteria in a short time, which, in turn, can hinder the process of biological cleaning and filtering of the tank water.

Taking advantage of the situation, various microbes and free-floating bacteria can emerge and cause cloudiness in the water. Hence, it is pretty common for your new tank to become cloudy due to such reasons.


If you are wondering why the water in my fish tank is cloudy, by now, you must have understood all the reasons behind it.

So now, all you can do is apply the different ways for how to get rid of white cloudy aquarium water. Keeping your aquarium water clean and tidy not only improves the visual appearance of your tank but also helps your fish to have a healthy aquatic environment.

Opting for the above-mentioned ways for removing cloudiness from your tank water helps your fish achieve enhanced immunity

and, at the same time, reduces the chances of infection in them. So, do not neglect it whenever you come across cloudy tank water; take the necessary actions immediately.