How to Treat Ich or White Spot Disease on Freshwater Fish

Ich is one of the most common diseases that your aquarium fish can encounter. Although there are many options for how to treat this condition, we have found that this is the most effective method. This is based upon more than a decade’s experience managing 100 to 200 fish tanks and importing wild-caught species.

What is Ich?

The Ichthyophthirius multifiliis prozoan, also known by the name ick or white spots disease, attaches itself to your fish’s body and fins. They form a tiny white capsule that is usually less than 1mm in diameter. After feeding off the fish and growing to maturity, it falls off the fish, encapsulates itself on the ground or other aquarium surface, and rapidly replicates itself. After the replication has been completed, the cyst bursts open and hundreds upon hundreds of ich protozoa can be released into the water. They are capable of swimming for up to three days before they find a host to attack. The earlier you catch and treat the ich, the better your fish’s chances of full recovery.

This microscopic view of ich shows it in its trophont stage. It is below the skin of the fish.

Does My Fish Have Ich?

An ich fish will look like it has tiny crystals all over its body. It’s almost like someone sprinkled salt on the fish. Because there is less slime in these areas, we tend to see ich first on the fins. It’s also easier for parasites to target. Other symptoms include loss of appetite and rapid breathing. Fish may also rub their bodies against surfaces or hide.

Five spots today may be caused by an external parasite. Tomorrow, it could be 35 spots. However, some fish get “stress ich” or stress spots, which evenly covers the entire body (not just the fins). Stress ich is when you see the same number of spots today as tomorrow, but with no increase. This may not respond to the treatment plan below.

In a rough analogy ich could be described as chickenpox. These are skin conditions caused by an infectious microbe. Stress acne is a condition that is caused by hormones. There are many treatments for chickenpox and stress acne. The same goes for ich. See our article on stress ich for more details.

Clown loaches may get ich especially if they don’t like the temperature of the water.

Can Ich Affect Humans?

Thankfully, no. You will not be infected if you touch the aquarium water. However, make sure to thoroughly wash your hands and forearms so that you will not accidentally pass the disease to other aquariums. Do not share siphons or nets among fish tanks. If you must reuse aquarium tools, you can disinfect them with very hot tap water and chlorine and then allow the items to completely dry before reuse.

What is the Best Ich Treatment for You?

There are numerous techniques for treating ich, from gentle herbal solutions to very invasive ones, but after years of testing, Aquarium Solutions Ich-X is our medication of choice. It’s very effective and safe to use with any fish (even scaleless ones), shrimp, snails, and live plants.

1. First, identify the disease and make sure it’s actually ich. Because velvet and stress ich look very similar it is worth waiting 24 hours to confirm diagnosis. 2. Dose Ich-X according to the instructions, which is 5 ml of medication per 10 gallons of aquarium water, and wait 24 hours. Do not give ich half-strength medication if you have sensitive fish. This concentration is not strong enough to kill them. We have never had to deal with any species of fish after treating thousands. 3. Change one-third of the water and dose the aquarium again at the same concentration of 5 ml of Ich-X per 10 gallons of water. Remember to add enough medication to treat the total water volume of the aquarium, not just the volume of the water removed. 4. Repeat Step 3 every 24 hours until you don’t see any signs of ich. 5. For one additional day after your last ich, complete Step 3. This is to make sure there are no cysts in the ground. The only way the medication can kill protozoa when they are free-swimming is if they are not enclosed in a cyst. 6. Leave the medication in the water and gradually remove it over time with your regular water change routine. 7. The fish’s body will have many wounds and tissue damages after treatment. This makes it an ideal environment to harbor fungal and bacterial pathogens. You may need to treat secondary infections.

The active ingredient in Ich-X is malachite green chloride, which has a strong blue coloration, so avoid touching the liquid if at all possible. In our experience, we have not noticed any problems with blue staining on aquarium decor or silicone.

If the symptoms don’t improve after five days, you may have misdiagnosed the disease. Do not continue treating Ich-X. You can gradually reduce it by following your regular water changes and then reevaluate the diagnosis.

Salt is another option for Ich-X if it isn’t available in your country. We often use it with cichlids (both African and South American) and goldfish, but catfish and loach species can be more sensitive to salinity changes. For more details on using salt to treat ich, read our blog post on aquarium salt.

Is Ich Always Present in Aquariums?

This is a hotly debated question among fish keepers, but regardless of the answer, the key is to always run your aquariums as if it is there. This disease is often opportunistic, and can occur when fish become stressed or weak. So try to find out why your fish got it. Did you introduce new fish to your aquarium without quarantining them first? Did the tank have rapid temperature and pH changes? It is possible to avoid future outbreaks of ich by maintaining a high water quality and minimising stress sources.

Fortunately, ich is one of the easiest diseases to treat, and fish generally will not die immediately from it (unless they already have a compromised immune system). Always keep a bottle of Ich-X on hand in case of emergencies because you don’t want to be forced to run to the store late at night and use a random product that may end up harming your fish. With the right medication and a bit of patience, your fish should be cleared up in no time from those pesky white spots.