Cloudy Goldfish Tank – The Ultimate Guide To Get Rid Of It

This entry is part 1 of 3 in the series How to get crystal clear water

It can be a bit frustrating to see your goldfish tank water become a complete mess.

We have all been there. We know how crazy that can be. But well, tank water has gone beyond the profit-making vibes that we all bury in our minds. There are of course a lot more to it, one of them is the cloudiness of your fish tank.

You know what strange is about this cloudiness thing?

Most times, what you see with your naked eye is just a mere change of your water from that fresh look to a milky white or probably brown color.

It is actually not that simple. It can be a huge sign that your goldfish tank lacks good hygiene. Maybe you are not adding the right proportions of chemicals to your goldfish tank, or you are just being careless even when you know what to do.

While you are at it, your fishes started to become a victim of your cloudy goldfish tank. There are lots more you can do to save the day. You may well figure it out here.

1. What Makes Your Goldfish Tank Cloudy?

You cannot possibly get rid of the cloudiness in a goldfish tank without having an idea about its causes. This is because there could be special causes. And each cause has a different treatment method.

It means you can’t treat bacteria-oriented cloudiness the same way you would treat algae-oriented cloudiness.

Let’s get down to the point. Cloudiness can be caused by a number of things.

When I say “a number of things”, you should know that there are whole lots of causes waiting for you right here.

Algae Bloom


Sometimes, the cloudiness of your goldfish tank may be very severe. So when all of a sudden, the milky white color of bacterial bloom turns green, then an algae bloom is sure at work.

Unlike bacterial bloom, algae bloom is easy to figure out with your naked eye.

With a thick greenish hue in your goldfish tank, you are sure to easily spot an algae bloom.

It is often perceived as the most frustrating form of cloudy water. You don’t want to invest your gaze on this ‘messy thick green water’.


Still wondering how these algae bloom thing storms your tank? Don’t worry.

The reasons are simple.

First, it usually starts when you overstock fishes in your tank or probably overfed them.

Second, it may be that there are overgrowing numbers of nutrient in your tank water. The nutrients may be nitrate and phosphate. It is sure to mess up the nice look of your goldfish tank water.

Still wondering how this phosphate and nitrate works. Your goldfish tank will definitely be invaded by these two nutrients when there are lots of decayed fish food and waste in your water.

Third, it may just be that your goldfish tank is exposed to excessive direct sunlight, or your tank lights have been switched on for a long time. It could stir up algae growth.

Finally, an algae bloom could occur if you fail to perform the weekly water changes.

Bacterial Bloom


Maybe you don’t know, one of the most common causes of cloudiness in a goldfish tank is bacterial bloom.

Certainly, some less harmful bacteria in your tank are the brain behind the constant maintenance of the nitrogen cycle. Of course, this nitrogen cycle keeps your tank super clean. But well, there are also other kinds of bacteria right there. These bacteria are quite harmful.

When a lot of these harmful bacteria invade your goldfish tank, your water becomes cloudy. And in the next few days, your water turns to a milky mess.

Sounds frustrating right? What’s more?

Strangely, bacterial bloom doesn’t just come. It seems to be addicted to a specific phase of a tank.

What am I talking about? Bacterial bloom has a more pronounced period when it invades your tank. It often shows up when your goldfish tank is still new and the environment inside of your tank is still prone to microorganisms of similar nature.

One more thing. If by any chance you figure it out in an old tank, it may be due to seasonal changes, for instance, hot periods.

Dirty Tank

Somehow, dirty water may also have a cloudy look with a slight yellow color in your tank.

High level of dissolved phosphates, silicates or heavy metals

Once you have thoroughly washed your gravel and you find out that the cloudy look is still looming over your goldfish tank, you should test the pH of your tank water.

When the pH level of your water is high in dissolved phosphate, silicates and metals, chances are that the cloudiness in your water is caused by them.

Gravel Residue

Let me say this straight, inadequately washed gravel can make your goldfish tank cloudy.

Are you wondering how? Once you filled your goldfish tank with water and it becomes cloudy afterwards, chances are that you didn’t wash your gravel as much you as you should.

2. How Do You Get Rid Of A Cloudy Goldfish Tank?

In many cases, all you just need to do is to watch the cloudiness of your goldfish tank leave on its own.

In other cases, you may just have to exercise a little patience and settle with simple routine maintenance.

But well, it can be frustrating when you simply can’t resolve the cloudiness of your goldfish tank even with these simple measures.

If you think the cloudiness of your goldfish tank may prolong more than you ever bargain for or you want to speed up the solution, this is why I have garnered some treatment methods that are bound to apply to each cause for you.

Treatment Methods

Algae Bloom

If you are quite sure that algae overgrowth might be the problem, here are a few treatment methods you should try.

Algae-eating fish


You may not know. Algae-eating fish are often a good way to deal with algae bloom and the cloudy look of your tank.

How do you get to use it?

Try to buy some algae-eating fish or snails that can feast on the algae on all corners of the tank. There you go. Your tank can become clean again with this simple tip.

Algaecide chemicals

If you aren’t really confident about the algae-eating fish thing, try some algaecide chemicals.

Use a Nitrate or phosphate filter media

Unlike other remedies, adding a nitrate or phosphate remover is more of a control measure than an instant solution.

Where am I going? After your tank water is completely free from cloudiness, try a nitrate and phosphate filter media.

A good example is Fluval Clearmax.


So what is the essence of it? It will minimize the likelihood of algae bloom in the long run.

Use Particulate clarifiers

Maybe you don’t know, you can also add clarifiers such as API ACCU-CLEAR to get rid of cloudy aquarium water.

Let me be honest with you, it may take a lot of persistent usages to clean your water completely but it sure does work.

Bacterial Bloom

Broad-spectrum antibiotic

If by any chance you think that the problem with your tank is bacteria, try to use a broad-spectrum antibiotic.

You can add seachem kanaplex, and the likes or contact a veterinarian for appropriate antibiotic treatments.

Seachem kanaplex


Sure enough, they are active against negative bacteria in your aquarium water. It is available in pet supply stores.

What’s more? When you decide to add a broad-spectrum antibiotic to resolve your cloudiness problem, you may need to exercise some patience.

This is because effective results may take a few weeks but whatever it is, it is definitely a good catch for cloudy water.

High level of dissolved phosphate, silicate and metal

Add water conditioners

You should treat your tank water with some water conditioners in these cases.

See also:

5 Best Tap Water Conditioners –Indispensable Things For Your Fishtank (2019-Review)

Use reverse osmosis water

Dirty Tank

Change your tank water

Once you can figure out what the problem is with your dirty tank, change your filter and do a 20-30% water change. While you change your water, remove excess fish food and waste from your gravel.

What’s more? How often do you need to perform this water change?

The answer is quite simple.

This depends on the capacity of the tank, the number of fish and whether or not you have a good filtration mechanism.

If your tank becomes dirty because of excess waste in your tank, a 20 percent water change per day until it becomes clean will perform the magic.

Add Water Clarifier

After you have performed a water change for your tank, you can well add water clarifier to speed up the clarity of your water.

See also:

6 Best Water Clarifiers for Freshwater and Saltwater Aquariums (Guide And Reviews)

Gravel Residue

Wash inadequately washed gravel

Imagine what it would be like to fill your tank with some water and in a twinkle of an eye, the tank turns cloudy.

It can be extremely frustrating. But well, there is one thing you can try. It may be that there is some inadequately washed gravel.

Still wondering how to break free from this? Simply drain the tank and wash the gravel until the water becomes clear. There you go.

3. Tips On Keeping A Goldfish Tank Clear

  • Ensure that your filter is always clean.
  • Do not expose your tank to sunlight. It spurs algae overgrowth.
  • Do not overfeed your fish. Eliminate the remnants of any uneaten food after a few minutes.
  • The consequences of overfeeding are fatal. Your tank will be exposed to a lot of algae.
  • Ensure you perform a water change regularly.
  • Do not use an overdose of any products you decide to use for your cloudiness problem.
  • In addition to maintaining the clarity of your goldfish tank, you can well install an EcoBio-stone in your goldfish tank.

Still wondering how this EcoBio-stone works? It is made from a natural volcanic stone that is garnished with some less harmful bacteria.

When I say less harmful bacteria, this stone is sure to regulate the nitrogen cycle of your tank and make it clean regularly.

You may never see the invasion of algae and bacterial bloom in your tank with EcoBio-stone around you.

Final Thoughts

Keeping your goldfish tank as clear as possible after a cloudy attack requires a bit of determination and consistency.

If you are to have a healthy goldfish, you should know that the above tips should be incorporated into your lifestyle just as you take your bath and eat every day.

You can’t possibly break free from these things. Somehow, they will come at you. This is because your tank water is naturally prone to things of such nature.

If by any chance the cloudiness in your goldfish tank persists after all these tips, you should perform water change frequently or probably contact the nearest veterinarian shop. Then you are good to go on your journey to a crystal clear goldfish tank.

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