What is White Cotton Like Stuff in My Aquarium

Are you noticing some white cotton-like stuff in the tank that seems to be unhealthy for your fish?

It means there is some infection present inside the tank. Most probably the fungus or maybe the bacterial attack. When these parasites start inhabiting the container, they form colonies of white cotton wool. In case, if you remain untreated they convert in brown or black mold, so, when you find white cotton buds swimming or attached to the surfaces then immediately show concern and move toward the preventive measures and treatment.

What is White Cotton Like Stuff in My Aquarium

Let’s first know about the causes and symptoms of the white molds. So, you can treat your aquarium accordingly and save water life.

What causes the growth of white cotton?

White cotton stuff does not start penetrating itself. There are few reasons behind that allow the growth of these parasites inside the aquarium. Furthermore, these infect the fish as well as tank environment. The common causes behind the growth of these molds are

  • Buying of the fish suffering from fin rot or bacterial infection
  • Overfeeding of fish and leftover allows the growth of fungus, bacteria or algae over it.
  • Dirty tank means you didn’t change the water and the waste of fish becomes food for fungus or some other parasite.
  • The water temperature is not controlled.

Where does cotton wool be present?

The signs of the presence of white cotton-like stuff include

  • White spots on the fish fin or tail
  • White cotton attached to the pebbles and pool decoration.
  • Presence on the surface and walls of the tank

When you see the water is not clear, and the glass of tank has a fluffy white layer, it means it is the time to maintain your tank and prevent the fish from getting the disease.

Treatment strategies

Once you find the sign of infection in the tank, you should apply the treatment. Otherwise, you may have to lose your aquatic pets. The treatment depends on the level of the disease.

  • Use salt bath technique for the fish
  • It is the standard method to treat the fish as well as a tank with parasitic infection you can do it by yourself. The steps for treating fish with this method are
  • Take four tablespoons of salt in the bucket or separate tank.
  • Add the water from the tank to make the level of one gallon
  • Mix the salt thoroughly, place the fish from the container in the bucket.
  • Keep it inside for five to thirty minutes depending on severity level.

Point to ponder

  • Observe the behavior of fish properly throughout treatment. If you see that the fish is not swimming well or feeling uncomfortable, immediately return it back to the original tank.
  • The method is not applicable for the scaleless fish as they can’t bear salt and may die. For that consult veterinary doctor to treat it.


Salt bath for the whole tank


When the infection is severe. Perhaps has been spread around the tank, then it’s essential to treat the whole container. The treatment method includes

  • Measure one teaspoon and dissolve in each gallon of water in the tank. Use a small separate bucket to do so.
  • Slowly add the solution in the tank.
  • Change 25% of water weekly.
  • Do not add extra salt when you start the treatment
  • Continue till you see a complete disappearance of the white molds in the tank.
  • Do not use the slat at home always prefer to buy the special aquarium salt having a consistency that the fish can resist.

Things To Focus

  • Measure the right quantity of the salt.
  • Make sure the salt is completely dissolved in water.

Tank Cleaning

Once you think that the whole molds are over now and you find no cotton bud inside the aquarium, then it means now you have to refresh your tank. For this purpose, follow the steps given below

  • Shift the fish to the quarantine tank with optimum temperature and pH so that it feels no distress in the new environment.
  • Take out all the decorations and fresh plants. Keep them away from the quarantine tank
  • Drain whole water. Try to drain outside the home so that no leftover spore can reattack to fish or tank.
  • Scrap the particles and residues.
  • Use the high-quality detergent to wash the tank thoroughly
  • Drain the soap and rinse two to three times with hot water. Make sure there is no leftover detergent, and the tank is cleaned thoroughly.
  • Place it under sunlight to dry as well as to remove any smell.
  • Meanwhile, wash the tank decorations. First, scrap all residues. Then soak in detergent to thoroughly clean.
  • Rinse with hot water two to three times.
  • Let them dry and place back to the already treated tank.
  • Fill the tank with water having nutrients optimum for the fish. Do not add water having chlorine, ammonia or nitrite in it.
  • Maintain the temperature of the tank.
  • Allow the fish to swim again in their tank.

Care To Prevent Mold Infection

Once you treat your fish and refresh your tank, it’s time to take care of the container. Otherwise, your fish may suffer from the parasitic attack, and maybe you get annoyed with all that stuff. so, to avoid inconvenience try to

  • Keep water clean and hygienic. Change it every two to three weeks.
  • Do not overfeed your fish. Commonly 15 minutes of feed is enough. Otherwise, the leftover becomes food for fungus and bacteria that give rise to cotton colonies.
  • Keep an eye on fish activity, if you feel that if it’s not swimming well or hiding behind the things, it means something wrong with it. Immediately check, so it gets treatment on time. Moreover, you will prevent the spreading of infection to the whole tank.

These are few caring strategies that you should adopt; otherwise, your fish tank may get infected and may create a frustrating condition for you.

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