Why is my betta fish tank cloudy?

In this blog we will discuss various reasons behind a cloudy betta tank.This blog will help new and experienced betta keepers,about what needs to be done when their betta tanks get cloudy and how to clear the cloudy betta tanks. 


In this blog

  • Why is my betta fish tank cloudy?
  • What are the reasons for a cloudy betta tank?
  • How to deal with bacterial blooms in a bettas tank?
  • How to deal with cloudy betta tanks?
  • What makes bettas aquarium water clear from cloudiness?
  • Types of gravel siphon for bettas tank to clear cloudiness
  • Summary 
  • Frequently asked questions
  • Reference 

Why is my betta fish tank cloudy?

After setting up a new tank, it is not uncommon for the aquarium to become cloudy.This is due to the colonization of beneficial nitrogen forming bacteria that oxidize ammonia and nitrite.

These bacteria break down fish waste, decaying plant matter, and uneaten food into ammonia.

What are the reasons for a cloudy betta tank?

Cloudiness or turbidity can be caused by dirty pebbles or gravels, bacterial blooms, and a change in water conditions.If the light is too green in the tank or there is too much phosphate,it could also be a bacterial bloom.

To treat turbid water in a betta tank, it is usually best to leave it to clean up alone.One ​​of the most common symptoms of cloudy betta water is how quickly it appears and disappears.

Dirty pebbles or gravels in bettas tank

The most common cause of turbid or cloudy water in a new aquarium is a substrate gravel. When the aquarium gravel and sand are new, it contains some dust and makes the aquarium water cloudy.

The new gravel and sand should be washed vigorously in a bucket with tap water until the water is crystal clear for your bettas to survive.

If the water is cloudy quickly, or within an hour or two of filling the tank, it may be due to inadequate cleaning of the gravel.Drain the tank and rinse the gravel until the water is clear.This should fix the problem.

Proper cleaning of new aquarium gravel is an important first step in maintaining pristine water conditions.

Gravel dust and debris can damage or even kill your betta fish.These small particles must not enter the freshwater aquarium environment as it is not good for bettas health.

If you have a healthy and balanced aquarium,you can go for months without cleaning the gravel.However, even with efficient tanks,it is advisable to clean the gravel at least once every 2-3 months.

Bacterial blooms in bettas tank

When bacteria bloom in the aquarium, the water becomes cloudy and milky for a few days. Water is significantly less transparent, but suspended particles are invisible to the naked eye.

Regular partial water changes and proper tank maintenance can usually prevent serious bacterial outbreaks.In the new tank, the bloom disappears as the nitrogen cycle is established and stabilized. 

Bacterial blooms occur 2-4 days after the fish are added to the aquarium.The cloudiness caused by the growth of early bacteria does not harm the inhabitants of the tank and disappears naturally.

If the water doesn’t clean after 10 days, talk to your aquarium adventure fish specialist.

Excessive phosphate in bettas tank

If cleaning the gravel does not fix the issue, the next possible cause of the turbid or cloudy water in the newly filled tank is high levels of soluble components such as phosphates, silicates and heavy metals.

Phosphate can create a harmful environment for betta fish. Accumulation of phosphate in the aquarium can cause algae outbreaks, lack oxygen in the water, and adversely affect the fish environment.

The most efficient way to get rid of phosphate is to evacuate the material with a fluval edge gravel cleaner.

This will remove more detritus and helps to prevent phosphorus stockpiling due to precipitated particulate matter.

Green algae bloom in bettas tank

The outbreak of green water is caused by a sudden population explosion of floating algae called phytoplankton.

Unlike other algae that grow on glass and aquarium objects, greenwater algae float around tanks and multiply billions in a short period of time,which is known as green algae bloom.This makes the betta water cloudy.

Change in water conditions in bettas tank

Changes in the water quality in the betta aquarium often cause the water to become cloudy.This is again due to bacteria in your tank. 

When bacteria start growing in the tank again, it can cause the tank to turn white and cloudy.This can be caused by factors such as pH changes and temperature changes.

Excessive light in betta tank

Algae will grow if the aquarium is exposed to direct sunlight or left on for a long time.

Reduce the amount of time the lights are on and move the aquarium out of direct sunlight.

If your tank is plagued by green turbid water, you need to reduce the amount of light.Algae breed in light.

Too many algae in the aquarium can get out of control.If necessary, cover the betta tank with a towel for 1 or 2 days to keep out light.

Overfeeding and overstocking bettas can make their tanks cloudy

Overfeeding a fighting fish can lead to cloudy water as uneaten food can decompose.Oversaturation of the aquarium or too many fish can also cause the water to become cloudy.

Excess waste,like excess food, releases ammonia and nitrite in the bettas tank which causes the tank to become cloudy.

If you feed your betta fish too much or if they eat too often, the water may become turbid or cloudy.

Leftover food can spoil and make the water cloudy.This can occur in large tanks, but it is also a common type of problem for well-maintained tanks too.

Remedy – Get rid of all moldy food and don’t feed your fish for a day or two. Use a gravel siphon cleaner to remove moldy food and at the same time make a small water change to improve the quality of  water 

How to deal with bacterial blooms in a bettas tank?

  • Adding betta fish into a tank which has not been treated for the chlorine & chloramines,with a tap water conditioner.
  • By doing water change with untreated chlorinated water as chlorine kills beneficial bacteria.
  • By performing the above two steps, the cloudiness in bettas water due to many reasons will clear off in some time.

How to deal with cloudy betta tanks?

  • The first and the foremost thing is to keep patience.
  • The second important thing is to start by seeding beneficial bacteria in the tank to proceed with the natural process. 
  • The third important thing is to perform regular filter maintenance.
  • The fourth important thing is to change the tank water regularly.
  • Lastly, not to overfeed your betta fish,underfeeding is fine but excess feeding is not suitable.

What makes bettas aquarium water clear from cloudiness? 

Filtration is the most basic way we keep aquarium water clear. There are three ways of filtering an aquarium water – mechanical, biological and chemical, which work together to keep the betta aquarium water clear and free from cloudiness.Get a right size filter for your aquarium.

Types of gravel siphon for bettas tank to clear cloudiness

Aquarium gravel cleaning siphon 

  • The automatic start valve makes it easier than ever to suck up water.
  • Just shake the vacuum cleaner up and down a few times while submerged in the aquarium and the water will start to flow automatically.
  • Ideal for rapid water changes and water flow by self-priming using up and down motion, efficiently separates debris from gravel.
  • This pump is easy to use and Ideal for gravel  cleaning.

Fluval Edge II Gravel Cleaner, White

  • Handy and effective aquarium cleaning tool. 
  • Sucks away dirt and debris from the aquarium. 
  • Built-in gravel guard to prevent clogging. 
  • Supplied with a 15″ long tube and an additional 15″ extension tube.


  • Excessive stock of aquatic organisms, too much light, high phosphate, excess nutrients cause water quality disruption and makes tank water cloudy.
  • Do not add many fish to the aquarium at once.As a general rule of thumb, you’ll need an inch of fish per gallon of water.
  • Remove debris such as rotten plants and leftover food, clean gravel regularly, and partially water replacing keeps the aquarium very clean and resolves most cases of bacterial bloom quickly.
  • Reduce feeding every 2 or 3 days, as this reduces excess food spoilage and helps the tank to get rid of cloudiness.
  • Reducing nutrients(overfeeding and overstocking),turning off aquarium lights,and making sure there is no direct sunlight will help prevent overpopulation of these algae and this in turn will clear the cloudy water.
  • Introduce good and beneficial bacterias in bettas tanks to avoid cloudiness.Adding good bacteria will help balance the aquarium.
  • You should also change the water regularly.If you’re not sure how much water you should change, it’s best to start with 10-15% per week.
  • Regular water changes will help the filter and tank by removing some bacteria from the tank.In addition to that, it will dilute any harmful bacteria and phosphate buildup in bettas tank.
  • When a lot of waste is putrefactive on the gravel, both bacteria and algae grow.This problem can be resolved by vacuuming the gravel in the tank at least once a week.
  • It’s not difficult to treat turbid water in a bettas tank.And if you do it right, you can enjoy a clean tank.

Frequently asked questions

How long does it take for cloudy water to clear in bettas aquarium?

The cloudiness is caused by beneficial floating bacteria that do not harm the fish and should disappear or settle down in about 1-2 days.

Can reverse osmosis clear tank cloudiness?

Reverse osmosis is excellent for filtering contaminants, including minerals, chlorine, and some larger bacteria.

Does carbon remove phosphates from the betta fish aquarium?

Yes, carbon helps remove phosphates from betta tanks.Activated carbon does not directly remove phosphates from water, but rather slowly breaks them down into other components.

Do cloudy waters have different colors?

The cloudy water in a betta aquarium will take on a different color depending on the cause.It will be white/gray or green and all have different reasons and require different treatment as well.