9 Reasons: Why is My Fish Tank Still Cloudy After Cleaning it (2023) 

A cloudy fish tank can be annoying, especially after the owner has worked hard to clean it. Even after scrubbing the walls and replacing the water, you may still find the water remains murky and unclear. It’s a common problem but needs to be evident for people who like to keep aquariums.

 There are several reasons why is my fish tank still cloudy after cleaning it. Understanding these causes can help you take the necessary steps to resolve the problem. In this article, we’ll look at some of the most common reasons why your fish pond might still be cloudy after you’ve cleaned it, and we’ll give you easy ways to clear it up. The whole essay will help you keep your fish pond clean and healthy, no matter how long you’ve been doing it or if you’re a beginner. Let’s start learning how to care for your aquarium best.

Reasons for Cloudy Water After Cleaning

  • Residual debris: Even after you clean your tank, there may still be some trash or organic matter in the water. The water can look cloudy because of this.
  • Overfeeding: If you feed your fish too much, too much food in the water reservoir will appear overcast.
  • Overcrowding: If too many fish are in a pond, their waste can be too much for the filtration system, making the water cloudy.
  • Poor water circulation: Cloudy water often results from material settling and building up due to insufficient water circulation.
  • Incorrect cleaning procedure: If you don’t clean your tank right, like using soap or other cleaning products, it can leave behind residues that can fog the water.
  • New tank syndrome: When you first set up a new tank, it may take a few weeks for the good bacteria to take hold and the water chemistry to be in balance. During this time, it might not be exciting.
  • A bacterial bloom: exists when the number of bacteria in the tank grows all of a sudden. It can happen when there is still much food to eat or when there is waste from fish in the water. The bacteria eat the organic matter and make cloudy waste products. These waste products can make the water dirty.
  • Algae bloom: lives often another cause of cloudy water. Algae grow well when they get sunlight and food like phosphates and nitrates. If your tank gets too much sun or you use tap water with many nutrients, you may get an algae bloom, which makes the water look cloudy.
  • Ammonia is a poisonous chemical made from fish waste and food that hasn’t been eaten. In a well-kept aquarium, the good bacteria change the harmful ammonia into the less toxic nitrite and then nitrate. During a water change, however, the sudden change in the chemistry of the water can cause the ammonia level to rise, making the water foggy. If your fish died How to Sterilize a Fish Tank After Fish Died

Why is My Fish Tank Still Cloudy After Cleaning it (Steps to Take)

  • Increase water changes: Increase the frequency and amount of water changes to remove excess waste and debris from the pond.
  • Check your filtration system: Make sure your filtration is working well and is big enough for the size of your tank and the number of fish you have.
  • Reduce feeding: Give your fish as much food as possible in a few minutes, and immediately remove any extra food.
  • Avoid overstocking: Remember that your water doesn’t have too many fish and that your fish have too much room.
  • Wait for the tank to stabilize: If you just set up a new pond, wait until the good bacteria take hold and the water chemistry is balanced before adding fish.
  • Limiting the amount: How much light your tank gets can help keep algae from growing. You can do this by putting your tank where it won’t get too much light or using a light timer to control how much light gets in.
  • Gravel Cleaning: Fish waste and food that has yet to be eaten can build up in tank bottom gravel, making the water taste terrible. Use a siphon and a vacuum to remove dirt from the rock.
  • Temperature Control: Fish don’t like it when the liquid level changes, so keeping it the same is essential. Check the water temperature with a thermometer and adjust the heater as needed.

Preventing Cloudy Water in a Fish Tank 

  1. Refrain from overfeeding your fish.
  2. Perform regular water changes (10-20% per week)
  3. Clean your filter regularly or replace it if necessary.
  4. Avoid overstocking your fish tank (one inch of fish per gallon of water)
  5. Keep your tank away from direct sunlight.
  6. Only add new decorations or plants to your tank after cleaning them first.
  7. Test your water regularly for ammonia, nitrite, and nitrate levels.
  8. Avoid putting too many chemicals, like algae-control products, in your tank, as they can upset your ecosystem.
  9. Use a gravel vacuum to empty the leftover food and residue tank during water changes.
  10. Add live plants to your tank to help absorb excess nutrients and prevent algae growth.


A cloudy fish tank can frustrate many aquarium owners even after a thorough cleaning. But if you know what causes dirty water, you can stop it from happening again and make the water clear again. It’s essential to take care of your fish tank and check the water quality regularly to avoid problems like cloudy water and ensure your aquatic pets are healthy and happy.

 Using the tips in this article, you can make a clean, clear place for your fish to live and grow. Remember to be patient and keep at it because maintaining a healthy fish tank requires constant care and attention. With the proper knowledge and tools, you can make an aquarium that is beautiful and full of life that you and your fish can enjoy for many years.


How do you clear up a cloudy fish tank?

To clear up a cloudy fish tank, try changing the water, cleaning the filter, and reducing overfeeding and overcrowding.

 Why is my fish tank cloudy even after cleaning?

After a tank cleaning: If the aquarium water is cloudy after the tank is cleaned, the filter is cleaned, or the gravel or substrate is stirred up, the problem may be caused by too much organic matter being released into the water and bacterial growth.

Why won’t my fish tank stop be cloudy?

It can happen if the aquarium is overfed since bacteria feed on food that has yet to be eaten. Too many fish in the tank for the size of the tank. More filtration for the size of your tank or the number of fish.

Will the cloudy fish tank go away?

The initial aquarium setup is routine. Bacteria bloom. Two days to two weeks should clear the clouds. After a week, a 10–15% partial water change and gravel vacuuming can speed it up.

How do I change my fish tank water without killing fish?

Check aquarium water temperature. Tropical fish need 25°C tank water.
Dechlorinate aquarium water. Chlorine kills pests and makes tap water safe to drink.
Change some aquarium water.

How do I know if there is ammonia in my fish tank?

More mucous.
Red gills.
Darkens skin.
Increased breathing and fish “gasp” at the surface.
Secondary infections.

Are fish more active when cloudy?

Fish are more active on cloudy days. But fishing on bright days is fine. Overcast days reduce water visibility. Clear skies mean more transparent water, higher temperatures, and fewer fish activity

Emma is the wordsmith behind the insightful articles and guides on our website. Her extensive research and passion for fishing shine through in every piece she creates. Whether sharing angling tips or delving into the latest conservation efforts, Emma is dedicated to providing valuable and engaging content.