White Spot on Fish Guide

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The last thing you want, when you bring fish into your home, is for your new friends to find themselves ill.

If, or when, your fish begins to act strangely, it’s natural that you’ll worry. In this case, it’s important to maintain a close eye on them, and observe both their behavior and their physical presentation in order to ensure that they remain as healthy as they possibly can.


Say that even with all of your close monitoring, one day you observe a white spot, or a cluster of white spots, focused on your fish’s fins.

White spots on fish are signs of White Spot Disease, or Ichthyophthirius multifiliis – an illness quite appropriately known as Ich.

These white spots that you’ve discovered are, in fact, parasites, and once they’ve made a home in your fish’s aquarium and on your fish’s body, it’s especially difficult to rid yourself of them.

Together we’ll explore some basic ways you can work to prevent your fish from becoming infected with these parasites, as well as how to combat Ich, should it settle in on one of your fish.

It’s worth keeping in mind, though, that Ich is a particularly potent fish disease; after it infects a fish, it has a ninety-five percent mortality rate unless treated immediately, and the disease is highly contagious.

When exposed to white spot treatment, fish have a better chance of surviving, but you’ll want to treat the whole of your tank in order to prevent its spreading.

Taking Preventative Measures for White Spots

If you’re looking to prevent any illness or additional stress in your fish, especially in the form of white spots on fish fins, then you should make sure you’ve done all that you can in order to ensure that your fish live in a stress-free and appropriate environment.

The kind of care that each breed of fish needs will vary, but consider all of the following factors when preparing a tank for your fish, as well as when interacting with them on a daily basis.

Prevention is the first step of treatment when it comes to the care and keeping of fish.

Aquarium Size

Contrary to the beliefs perpetuated by pop culture, fish cannot live healthily in undersized bowls.

Each breed of fish has its own aquatic requirements. This means that determining the appropriate size of the tank will be much simpler if you only house one breed of fish.

white spots on fish fins

If you’re looking to establish a community tank, however, you’ll want to take the needs of all your fishy friends into account.

When assessing the health of your fish, you’ll want to ensure that the environment in which the fish lives is the one best suited for them.

Is the aquarium you’ve placed your fish in large enough? Or is it too large after all? If your fish of a breed that is particularly territorial? Is there enough room for said fish to carve out its own personal space?

All of these elements factor in to your fish’s stress levels and, in turn, their overall health.

Aquarium Arrangement

The arrangement of stimulating elements in your aquarium can impact your fish’s health, just as the size of the aquarium can.

Each breed of fish will have different reactions to different forms of stimulation, meaning that some will respond positively to busy tanks, and others will react by hiding so that they don’t have to worry about the wealth of objects in their environment.

Make sure that your fish has plenty of space to hide, so they can recover from something that makes them uncomfortable.

Additionally, double check and make sure that the plants you choose for your fish tank are ones that either can be found in your fish’s natural habitat, or that have been proven to make your fish comfortable.

It’s possible that parasites could enter into your aquarium by riding on the leaves of plants you’ve purchased, so do take care to buy these plants from trustworthy sources.Much the same can be said for other forms of tank decoration like substrate, rocks, and hidey holes.

If you feel especially worried, clean your tank decorations once a week or so, with non-toxic soap, and examine them carefully for any signs of mold or unexpected fauna. These preventative steps will help you go far in taking care of your fish’s health.


Not only is the set-up of your aquarium important, but the hardness and pH of the water inside can have immediate impacts on the health of your fish.

As we’ve stated, each breed of fish has its own needs. When you’re creating an aquarium for a single breed of fish, establishing the pH and hardness of the water is simple – you don’t have to find a compromise between one fish’s needs and any others. However, community tanks require some careful consideration.

When establishing a community tank, it’s best to partner up fish that come from similar natural habitats.

white spots on fish fins

Dwarf gouramis, for example, need to be partnered with other labyrinth fish, or fish whose natural habitat finds them in water that is not well oxygenated and leans toward temperate.

If you do end up placing incompatible fish in the same tank, the lack of balance in the water could lead to sickness in one particular breed.

White Spot Disease, however, impacts all breeds of fish, regardless of their natural habitat, but you do not want the parasites to be aided in any way by weakening one breed of fish’s immune system.


It may be simple to say that you need to feed your fish regularly, but ensuring that your fish aren’t overfed, underfed, or inappropriately fed is just as important in the prevention of White Spot Disease.

Fish diets vary. Some breeds are purely herbivores, some are omnivores, and others are strictly carnivorous. That being said, you still want to balance your fish’s diet and ensure that they’re receiving all the nutrients they need in order to keep their immune systems operating at top form.

Do not overfeed your fish. While these critters can’t beg, like cats and dogs, it can still be tempting to reward your fish for keeping you company or improving your mood with a tasty treat.

Consider adding alternative forms of enrichment to your fish’s tank, instead, while remembering that by keeping your fish’s diet balanced and securing their health, you’re thanking them in one of the best ways possible.

Facing White Spots

Even if you do everything right, though, it’s still possible that your fish will contract White Spot Disease. It happens even under the watchful care of expert aquarists!

White Spot Disease, as previously mentioned, arrives when a particular parasite enters your fish’s tank and begins to settle on your fish’s scales.

The parasite enters the tank through new plants, toys, or other breeds of fish.

White Spot Disease does not just impact one breed of fish in particular; instead, white spots on tropical fish can transfer to non-temperate fish with ease, should you accidentally share toys or plants between tanks.

Identifying White Spots Disease

There are several signs indicating that your tank has fallen victim to White Spot Disease, even beyond the titular white spots.

However, you’ll notice the condition right away if your fish develops small (even smaller than you’d expect) spots, roughly the size of a pin.

They tend to congregate on your fish’s fins, but they can also appear on the head, body, and tail in large numbers.

white spot on fish

Beyond this, you may notice that your fish begin sipping at air far more frequently than usual. This occurs because White Spot Disease makes it significantly more difficult for your fish to breathe, and they’ll be attempting to get air into their systems any way they can.

It’s also likely that your fish’s eyes will start to protrude from their heads. Swollen eyes can be a sign of any number of illnesses, but swollen eyes partnered with any of the above symptoms of White Spots Disease is fairly bad news for you and your fish.

Finally, if your fish is having significant trouble swimming (if they’re bumping into the glass of the tank, each other, or swimming upside down or at odd angles) then you’ll want to assess their health as soon as possible.

White Spot Treatment

White spot treatment varies depending on the types of symptoms your fish displays.

If your fish begins swimming towards the surface of the tank more frequently, in order to take sips of air, check the pH level of the water in your tank.

It’s possible that the pH may be unbalanced, and that by readjusting it through chemical tinkering, you’ll be able to re-establish your fish’s health and ability to breathe. You’ll also want to seek out anti-biotic, anti-parasitic medication to spread throughout your tank.

If your fish’s eyes are protruding from their head, and you’ve found other signs of White Spot Disease in your tank, raise the temperature of the water in your tank to the highest that your particular breed of fish is comfortable with.

The extra heat will kill off the parasites and relax the muscles of your fish’s body, making them more comfortable, reducing the swelling of their eyes, and allowing them to become more healthy.

If you notice clusters of white spots on your fish’s body, then you’ll want to introduce malachite green dye into your tank. This dye will disrupt the life cycle of the parasites and force them away from your fish, bettering your fish’s chance for survival.

You’ll then want to quarantine the infected fish, as well, since White Spot Disease is highly contagious.

Here’s a video showing more details on white spot treatment.

Have you had to deal with white spots on fish fins?

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