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. Many different approaches exist for combating this illness, but based on more than a decade of experience running 100 to 200 tanks in a fish store and importing wild-caught species, this is our go-to method for treating ich.
What is Ich?
Also known as ick or white spot disease, the Ichthyophthirius multifiliis protozoan is an external parasite that attaches to your fish’s fins, body, and gills by forming a tiny white capsule (usually less than 1 mm 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. Once the replication is complete, the cyst breaks open and hundreds of new ich protozoa are released into the water, capable of swimming for two to three days until they locate a new host to attack. The better the chance that your fish will fully recover if caught and treated early.
This microscopic view shows ich in its trophont stage, feeding under the skin of the fish.
Does My Fish Have Ich?
Fish with ich often looks like they have tiny crystals covering their bodies, similar to salt being sprinkled on them. 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. Stress ich is a condition that affects fish and covers their entire body (not just their 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 could be described as chickenpox. These are skin conditions caused by an infectious microbe. Stress acne is a condition that is caused by hormones. 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. You should not share equipment, such as siphons or nets, between 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 is safe and effective for all fish, shrimp, snails, live plants, and scaleless fish.
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. After treating thousands upon thousands of fish, we have never encountered a problem with any other 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. You can repeat Step 3 every 24-hours until you see no signs of ich. 5. Complete Step 3 for one extra day after you last see ich on your fish, just in case there any cysts hiding in the ground. (The only time the medication can kill the protozoa is when they’re free-swimming and not protected within a cyst.) 6. You can leave the medication in the water, and slowly remove it with your regular water changing routine. 7. After treatment, the fish’s body has lots of wounds and tissue damage, making it an ideal environment for bacterial and fungal pathogens, so you may need to treat for 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 there’s no improvement after 5 days, the disease was mostly likely misdiagnosed, and you are not dealing with ich. Stop treating with Ich-X, gradually remove it using your normal water change schedule, and reevaluate the diagnosis.
Also, if Ich-X is not available in your country, salt is another good method for treating ich. 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. 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? Were the conditions in your fish tank poor? Did they experience rapid changes in temperature or pH? 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). 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.