cloudy fish tank

An Answer to The Most Asked Question ‘Why is My Fish Tank Cloudy’


What the heck! Where are my fishes? Where they went? I want them back. But wait where they can go? They can’t walk like me. And what is this cloudy thing floating? Why is my fish tank cloudy? Oh, my poor, Bruce, Larry, Cleo, and Dora. I hope they are getting enough air to breathe…You also experienced the same thing?  There can be specific reasons and causes that resulted in a cloudy fish tank. But changing the water every time isn’t the solution.

Not a big deal. Once in a lifetime, every aquarium lover faces this situation. But don’t worry, it is treatable. What on earth isn’t curable except crazy lover! Haha! Now, as you are here, let’s face it. There are steps that you should follow to minimize the problem. Any problem-solving needs three steps, defining a problem, its analysis, and the final step is solution designing. After that, implement the solution and have the evaluation.

So here you know the problem, its Cloudy Fish Tank. 

Now you need to define it. Then you need to know where the problem lies, and the final step is how to fix the problem. Once you are aware of fixing the problem, the rest two steps are to be conducted by you at your place.

Also Read: 5 Best Fish Bowl For Your Fishes

So let’s start with,

What is a Cloudy Fish Tank?

cloudy fish tank


Let’s keep it in a simple way when you see a shadowy figure of fish floating in the water instead of beautiful and colorful fish playing around and making bubbles when the crystal clear water turns into grayish or greenish, my friend that is the cloudy fish tank. It isn’t that harmful, but the extreme situation may kill your lovelies.

Calm down; we won’t let that happen. Now you know about the cloudy fish tank, let’s move on to your asked question,

Why Is My Fish Tank Cloudy and What Can I Do About It?

There can be two situations of your aquarium right now, either it is more like whitish/grayish, or it is greenish. Both have their own causes. But you need to know about it to pacify your baffling mind.

We will talk about every situation of the water in your aquarium with its solution. First is…

White or Grayish Water


If the water in the fish tank looks like someone has added a white or gray color to it. Then there can be three causes: 

  • Residue of Gravels
  • Dissolved Constituents
  • Bacterial Bloom

The residue of Gravels:

If you find your tank whitish or grayish just after filling the tank. Its nothing but the residue of the gravels you placed. Empty the tank and wash the gravel until you see the clear water. 

Dissolved Constituents:

If still your water seems contaminated, then it’s because of dissolved constituents. There are chances that you might have dissolved the components more than needed. These components include phosphates, silicates, or heavy metals. To identify whether it is a problem or not, you will have to test the water.

If you see a high pH level, then it is the sign that high-level constituents are making your aquarium cloudy. Its solution is simple, treat the water with conditioners. But if it still doesn’t show the effect, try using RO water (best option to go for!).

Bacterial Bloom: 

If it’s already been weeks or months, and now you see the grayish water, then it is definitely because of bacterial bloom. Bacterial bloom is the population explosion of heterotrophic bacterias. There are autotrophic bacteria already present in your filter, and they feed on the inorganic substances. Heterotrophic bacterias feed on organic substances and are present in almost all the water bodies in the background.

But their number increases when there is much organic food to feed on. These bacterias are not harmful to your fishes, but an excess of them are! They are the reason why the waste of fish rots and produce ammonia (which is a good thing!). Though it doesn’t kill the fish directly, it does impact the quality of the water, which eventually results in the death of fishes. The solution is to avoid the overfeeding, overcrowding, over-cleaning of the filter, and dead fish in the tank for a longer time.

Click here to know how to clean the fish tank.

Another is,

Greenish Water

cloudy fish tank


If your water is greenish in color like mountain dew, then it’s a low hanging fruit. It is because of algae growth. Green water isn’t harmful to your fishes; it just looks awful, and you can’t see your beauties. It’s easy to cure. Like having a cup of tea! But before that, make yourself aware of three components that result in green water:

  • Light
  • Phosphates
  • Nitrates

Excess Exposure to Light:

Excess light or direct sunlight is the main reason for green water. Light supports algae growth. The best solution is to avoid the direct sunlight hitting the aquarium or place the aquarium where there isn’t much light.


It work as steroids for algae. Phosphates are a result of two things – water itself and food decay. Check the phosphate level of water; if it’s high, you need to change the water. And it’s better if you switch of RO water. Another thing is food decay that happens because of excess food in the tank for a longer time. The solution is proper cleaning of a fish tank and avoiding overfeeding.


Nitrates are the byproducts of fish waste (debris). The only option to remove it through water change make sure your filter is clean and adequate for the size of your aquarium. Don’t overstock the tank, or you will face the problem on a regular basis.

cloudy fish tank


Here are some of the best home for your aquatic friend.

We know, that was a heck of information in one go, but now you know every single reason behind the fuzzy and cloudy aquarium. Why weren’t you able to see your lovely fishes? And you know the solutions too. So what are you waiting for? Hurry up and move on to the next steps (implementation and evaluation). To know more about different types of fishes and other pets visit Petsnurturing.


Ruby Jennifer

Hi, I am Ruby Jennifer a blogger. The main motive to create this site is that I want to share knowledge about Pets Information, Stories, Pet Breeds, and tips for grooming with all the pet lovers out there.