Dealing With Colored Water Aquarium

Dealing With Colored Water Aquarium


Aquariums look good only when they boast a transparent view with clear water. But sometimes, due to different reasons, the water turns green, yellow, or brown, making the water cloudy and unpleasant. It is very important for the tank to have clear water. It not only makes the aquarium looks good but also ensures a healthy water ecosystem for the aquatic lives swimming inside it. 

Let us find out how the color of water changes and the ways we can prevent it.


Algae are one of the root causes of the green water aquarium. The unpleasant green sight is due to an algal bloom that may appear in the tank from time to time. There are thousands of species of algae, and all of them are aquatic. Just like aquatic plants, algae also require water and light for photosynthesis and creating energy for growth. 

Freshwater green algae are more commonly found in aquariums. Although freshwater algae are useful to the tank to some extent as they act as food to some of the fish and snails, excess of them creates problems. A little amount is also suitable for aquascaping. However, when their growth gets out of control, the water turns murky and opaque and reduces the transparency of water. If left untreated, the water may turn so green that the fish will not be even noticeable. 

What causes algae bloom?

Some of the most common reasons for algae bloom are-

  • Direct Sunlight– Since algae photosynthesize light, excess of light or its direct exposure may cause algae to grow abruptly. 
  • Over-crowded Tank– When there are a lot of fish in the tank, the quantity of organic waste increases, providing nutrients for the plants causing algae growth.
  • Overfeeding the Fish– Most of the foods remain uneaten when you overfeed your fish. The leftover food becomes nutrient that algae use to grow rapidly.  

Other than these, water quality is also one of the crucial factors that may cause algae to grow. However, the best thing is, no matter how unpleasant the tank may look with algae, it is safe and not toxic to the fish. 

How to prevent algae bloom?

You can use any of the following methods or a combination of them to prevent the growth of algae. It will also keep their growth within your control.

  • Prevent photosynthesis by blocking the different sources of light completely. 
  • Get rid of suspended algae in the water by installing a diatomic or micron filtration system.
  • Introduce algae eaters like small crustacean daphnia that feed on algae and reduce their quantity. Later, they are eaten by the fish.
  • Put some snails or shrimps that eat fish. 
  • Change the aquarium water regularly
  • Clean the aquarium regularly
  • Use UV filter in the tank
  • Avoid overfeeding, direct sunlight, and overstocking the tank. 

If you are keeping your tank clean and changing its water regularly, the chances of algae bloom will subside. It is one of the best preventive measures that will rule out the possibilities of facing more severe problems with intense algae growth. Take prompt actions as soon as you encounter green water to have a beautiful tank.


Cloudy water is another serious problem in aquariums. And the thing that makes it more dangerous is its unknown causal factors. We call it cloudy aquarium when the water turns white or grayish. Although the exact reasons are not known, the cause of cloudy water could be one of the following-

  • Gravel Residues– If you see the water turning cloudy within an hour of filling it, the reason could be gravel residues. It is advised to always wash the gravel thoroughly before introducing it in the tank. Now, you have to drain the tank and rinse the gravel. Repeat rinsing until the water becomes clear to overcome the cloudy water.


  • Dissolved Constituents– Another reason for cloudy water is the presence of dissolved components like phosphate, silicate, and other heavy metals. If washing the gravel is not resolving the issue, a high level of such dissolved constituents could be the culprit. To ensure this reason check the pH of water. If it comes out to be highly alkaline, you have to treat the water with a water conditioner. Another way is using Reverse Osmosis water in the tank. 


  • Bacterial Bloom– Unlike green water, cloudy water doesn’t appear all of a sudden or overnight. It may take weeks for the water to turn white or grayish Bacterial bloom is another reason that causes cloudy water. If you have set up a new aquarium, it will undergo an initial break-in cycle that causes water to become hazy. Once the bacterial colonies establish, they clear the wastes, and the water gets clear. Bacterial bloom also arises when the tank has a large amount of uneaten food. It turns the water milky. 

How to prevent cloudy water?

No matter what is the cause, do not panic, seeing the water turning cloudy. You can do the following to overcome cloudy water aquarium-

  • Maintain a regular cleaning schedule of your tank.
  • Remove the decaying plants and the excess of uneaten food that invites bacteria to grow and make the water unclear. 
  • Vacuum out the gravel regularly 
  • Perform partial water changes for quick resolving the bacterial blooms
  • Do not overfeed the fish 
  • Use flocculant, also called water clarifiers to remove small particles of debris. Flocculants clump the small particles together and make them easily removable by the filter. 

The majority of cases of cloudy water are easy to resolve. Using thoroughly clean gravel, maintain the water quality, and performing weekly 10 to 15% of water changes, make sure that the water will remain clear.


There is not only one reason that may cause water to turn yellow or brown. Some of the most common reasons we can pinpoint are the following-

  • Bacterial Bloom– Unexpected brownish or yellowish water in the aquarium could be the result of bacterial bloom. Overgrowth of bacteria causes cloudiness, and the water may change the color from transparent to white, gray, yellow, or brown. It is very important to take immediate action before colored water causes any health hazard to the fish. 


  • Dissolved Organic Compounds– The yellow or brown tint in the water could also come from dissolved organic compounds. These are the organic matters that are produced when the uneaten food or the dead and decaying plants break down. The decomposing fish parts do the same and increase the content of organic compounds in the water. 

 Organic compounds dissolve in the water, change the water chemistry, and impact the overall health of the fish. Apart from changing the color of the aquarium water, dissolved organic compounds also give unpleasant smell and make the entire aquarium repulsive. 

  • Tannins– Although tannins are one of the causal reasons for yellow or brown water, thankfully, it is not harmful. If you have used driftwood in your aquarium for aquascaping, the tannins present in them may leach into the water, staining it into yellow-brown color. Tannins, in fact, are considered good for fish health and are often recommended to add in the tank. They lower the pH of the water and soften it. 

Troubleshooting Steps

Below are the indicators that can help you prevent the water from discoloration. 

  • Test the water. Take the water testing kit and determine the values of ammonia, nitrate, and nitrite. Also, check the water pH. 


  • Check out the debris present in the water. Remove all the uneaten and leftover food present on the substrate and dead and decaying plants. At the same time, see whether any of the fish are missing from the tank. The fish corpse could contaminate the water drastically.


  • Water discoloration due to tannins could be neglected.
  • Check whether your filter is running properly or not. 
  • Check for the foams on the water and any unpleasant smell. 


So these are some of the possible reasons why the color of the aquarium changes to green, white, yellow, or brown and how you can prevent them from occurring. Keep a healthy water ecosystem to retain the beauty of the tank and give a compatible ambiance to your aquatic creatures. 

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