White Film On Goldfish – How To Treat?

We frequently receive inquiries regarding goldfish care from new hobbyists because goldfish are deemed the most widely raised fish in the world.

These questions can span a wide range of subjects, but one query we have recently been asked is about a white film on goldfish and how to treat it.

If this is also what’s on your mind, keep scrolling down to see!

What Is a Slime Coat On Goldfish?

Slime coat is made of glycoproteins, which is the first line of defense against everything from big foreign objects to tiny germs. 

This barrier also keeps the fish’s vital electrolyte levels and fluids in check, lowering surface resistance and permitting the fish to float through the water more easily.


Like humans, goldfish have multiple layers of skin. They contain skin (dermis) that becomes scabs, followed by a thin epidermis that covers the scales. 

The slime coat is produced by goblet cells in the epidermis; any rupture of the outer layer of sebum is comparable to abrasion of the top layer of our skin. Losing a significant portion of their coverage would damage an important part of their skin.

Is White Film On A Goldfish Natural?

Unlike slime coats, it is quite uncommon for a normal goldfish to have a white film coating them. Instead, white films on goldfish are nearly typically the result of fish with underlying health issues.

White slime is rare even when the regular slime production of goldfish is limited by factors such as a poor diet or advanced age.

White Film On Goldfish


What Are The Causes Of White Film On Goldfish? How To Treat?

The three most frequent reasons for the white film on your fish are ammonia burns, several types of fungal infections, and columnaris infectious diseases.

Fortunately, a white film coating a goldfish is typically simple to treat, and most goldfish will recover completely without much of a hassle. 

Ammonia Burns

Ammonia burns are the least frequent reason for your fish to develop a white coating and are typically quite simple to avoid. Still, the damage could be permanent once your goldfish suffers from a chemical burn.

The white film does not represent the only sign of ammonia burns. It’s possible to detect the burns with some other more prevalent symptoms.

Also, you can determine the ammonia level to see whether this might be the issue with your tank by using the water test kit. If the level in your aquarium is too high, your fish may suffer from chemical burns, and white coating is a sign of this.

Your fish may have red gills due to inflammation from ammonia burning, which is another indication that the ammonia cycle is present in your aquarium.

We advise you to apply partial water change to your tanks in which they replace 10% to 25% of the water once every week. 

This will typically be sufficient to keep your aquarium’s ammonia process under control and keep the amounts of ammonia from rising to the point where they could result in burn injuries.

goldfish in aquarium

Fungal Infections

Aquarium fish frequently have fungal infections, and even seasoned aquarium keepers occasionally face disease outbreaks.

A fungal spore may enter an aquarium quite easily. Since most goldfish settings are the ideal breeding ground for the fungi, this spore swiftly multiplies until you are afflicted before you realize it entirely invades your tank.

Numerous fungus species can adhere to your tank and result in issues with white slime, white membranes, or white fluff appearing on your goldfish.

Luckily, these fungal infections can easily be treated using affordable, widely available medications like Pimafix, with most cases being resolved within a few days. And after two weeks, your fish might look better.

Take it immediately if you feel your fish has a fungal infection. Like with many diseases in fish, the more time you wait to cure it, the more challenging it will be. Start the right course of treatment as soon as you can.


Compared to a fungal infection, Columnaris is far less common. It is a bacterial disease that can rapidly adhere to your fish and create a white film to develop on their scales.

When you add additional rock, plants, substrates, species, or raw food to your tank, Columnaris is unintentionally introduced, as you allow bacteria to get inside your aquarium.

Since so many people are keeping plants and stone in their aquariums, there is a slow but steady increase in the number of individuals who report difficulties with Columnaris.

Fortunately, it’s simple to fix if you spot Columnaris in time. From our perspective, using Melafix and Pimafix simultaneously in your tank is the best approach to quickly, conveniently, and affordably treat Columnaris.

How To Prevent White Film On Goldfish?

Having the right treatments will solve the white film problems on your goldfish!

Avoid Handling Fish

Whenever possible, stay away from the fish. The fish’s slime coat will be significantly less harmed if you don’t touch it by hand or catch it with a cup. 

For the best result, you should use a net. If you have to use your hand, put on moist rubber or soft vinyl gloves, and you must wet or moisten your hands first.

Maintain Good Water Quality

One of the major contributors to fish stress, which then, in turn, harms the slime coating, is keeping inadequate water quality. 

Regular water replacements, tank maintenance, water testing, and actions to reduce growing pollutants like ammonia are all recommended. 

Avoid allowing the water to shift temperature quickly because this adds additional stress to your goldfish.

Good Water Quality fo goldfish

Aquarium Products 

You can buy things at your local fish store to encourage healthy slime coats and repair broken coatings. These items include aloe vera or polyvinylpyrrolidone, which stick to the goldfish’s skin and enhance the slime. 

Utilizing these goods is a wonderful way to protect your fish from sickness and stress.


The causes of white film on goldfish mostly happen due to the three main causes we mentioned above. Although dangerous, if you treat it properly, your goldfish will be able to return to normal. 

Thank you for following this article. See you later.