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. There are many ways to combat this disease, but this method is the best. It’s based on over a decade of experience in managing 100-200 tanks in a fish shop 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 cyst has broken open, hundreds of new ich prozoa are released into water. These protozoa can swim for two to three more days until they find a new host. The earlier you catch and treat the ich, the better your fish’s chances of full recovery.

This microscopic view shows ich in its trophont stage, feeding under 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 rapid breathing, loss of appetite, fish rubbing against surfaces, hiding behavior, and lethargy.

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). If you see five spots today and the same number of spots tomorrow with no increase, this may be stress ich instead and will not necessarily respond to the same treatment regimen mentioned below.

In a rough analogy, ich can be compared to chickenpox, which are contagious spots caused by an infectious microbe. Stress ich can be compared to stress acne, which are hormonally-caused spots that are not contagious. Treatments for chickenpox are different from those for stress acne. Check out our article on stressich for more details.

Clown loaches are prone to ich, especially if the water temperature is not high enough for their liking.

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?

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, you need to identify the illness and confirm that it is 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. For sensitive fish, do not use a half-strength dose as it will not kill the ich. After treating thousands of fish, we have never seen a problem with any species.) 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. Continue to repeat Step 3 for every 24 hours, until you no longer see any signs or symptoms of ich. 5. Continue Step 3 one more day after last seeing ich on your fish. This is just in case any cysts are hiding 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. After treatment, the fish’s tissues are damaged and there are many more wounds. It is an ideal environment for fungal and bacterial infections. Secondary infections may be necessary.

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 you don’t see improvement in 5 days, it is likely that the disease has been misdiagnosed. Do not continue treating Ich-X. You can gradually reduce it by following your regular water changes and then reevaluate the diagnosis.

You can also use salt to treat Ich-X if Ich-X cannot be found in your area. It is often used with goldfish, cichlids (both African- and South American), and cichlids. However, salt can also be used to treat ich in catfish and loach species. 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. Opportunistic diseases are common in fish that are stressed or weak. Find out the reason your fish have ich. Did you introduce new fish to your aquarium without quarantining them first? Was the fish tank poorly maintained, or were there rapid changes in parameters such as pH and temperature? You can avoid future outbreaks by keeping your water quality high and minimizing stress sources.

Fortunately, ich can be treated quickly and most fish will survive it, even if they already have compromised immune systems. In case of emergency, keep a small amount of Ich-X with you. This is because you don’t want to be forced into running to the grocery store at midnight to buy a random product that could endanger your fish. You can get rid of those white spots quickly with the right medication, patience and some good advice.