How Long Can Ich Live On a Fish? [Numbers & Facts] 

Quote– Aquarium fish make us realize how beautiful silence is

Ich, as I discovered, completes its life cycle in around 6 days from the first time it is seen on your fish to the next time it spreads. Given a typical aquarium environment, this assumes a temperature of 78 degrees. Your fish will continue to get sick until you break the cycle.

Sometimes a fish can have an infection of Ich solely in its gills and never display any symptoms elsewhere.

Ich, in my experience, can thrive for a long time on a diet of certain exotic fishes. They go through phases, but things always turn out well in the end. Everyone has ich, and the only way to prevent it from spreading is to keep your fish properly nourished and do regular water changes.

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However in some cases, unless you empty the tank and don’t put any fish back in for at least 8 weeks, you may always have Ich. If there are fish in the tank, the parasite will have a source of food and will continue to grow and spread. Many fish will develop resistance to the parasite, but it will still be around.

Everyone’s immune system is full of Ich, however, those that quarantine their fish appropriately typically have Ich-free aquariums. Only the parasites that happen to be pulled by your UV light will be killed, and only while they are in the free-swimming stage of their life cycle. Your fish may develop an immunity to the parasite and you may never see it again. 

What is Ich in fish?

Ich is a white spot disease caused by the parasite Ichthyophthirius multifiliis on fish. Ich appears as a small, white spot on your fish’s skin. The Ich parasite enters the fish through the skin or gills, burrows beneath the surface, and consumes the flesh. These lesions emerge on the fish’s skin or fins as tiny white spots, blisters, or grains of salt. On white or pale fish, or if the illness is confined to the gills, the white patches may be less noticeable.

Ich has a high mortality rate and is extremely contagious. If you have multiple fish in your tank, they are all likely infected. 

Once infected, your fish will develop white, raised blister spots at the site of the parasite’s penetration, and the parasite will multiply rapidly. After feeding on the fish, the parasite detaches and multiplies into thousands. 

Ich has a temperature-dependent life cycle, with fewer days between stages of growth in warmer water and a longer delay in colder water. Ich is particularly common in aquariums.

How do fish get Ich?

Ich is so common that it is present in the environment of most aquariums, particularly larger holding tanks and rearing ponds used by breeders, collectors, and wholesalers. Almost every aquarium fish will come into contact with this protozoan at least once during its lifetime. 

Because the disease is so common, most fish have developed a strong immune response to it, allowing them to fight off the protozoal infection before it causes any symptoms. With Ich being so common, it’s no surprise that many newly purchased fish are infected.

How do you treat fish Ich?

Since the life cycle depends on temperature and Ich can only be killed when it is in the initial stage, we will need to raise the temperature of the tank to between 78 and 80 degrees Fahrenheit over 48 hours to speed up the formation and release of Tomites. At this temperature, if the cycle takes four days to finish, the treatment should also be done in four days. On the other hand, if the temperature is much lower, like 60 °F, the treatment would need to last for several weeks or longer.

Since we know that Ich can’t be killed while it’s on the fish, we know that putting a sick fish in a quarantine tank won’t solve the problem in the main tank. Before putting a new fish in a tank for people to see, you should use a quarantine tank. If one fish in a tank has Ich, you have to assume that the whole tank has it and needs to be treated.  

In addition to this, you can cure your fish for Ich by following the necessary procedures and directions that are suggested below.

  • Before you start any treatment, get rid of any carbon in the filter, because it will make the medicine useless.
  • Increase the temperature of the aquarium by 4°F. This speeds up the parasite’s life cycle so it can be killed more quickly.
  • In the water add aquarium salt. The salt cleans the water by slowly letting oxygen into it, and it also makes parasites fall off of the fish’s skin. Different fish can handle different amounts of salt. Plant growth may also be affected by how much salt is in the soil.
  • Put some medicine in the water.

What are the symptoms of Ich in fish?

The most noticeable symptom of an Ich infestation in fish is the appearance of white patches all over the body. They can be as small as a tiny dot or as big as a grain of sugar. However, in my personal experience, I have seen that stress, and not Ich, may cause white patches in some fish. The absence of a significant increase in spot count suggests that the problem is most likely stress rather than Ich.

Your fish can be scratching an itchy place caused by a parasite if it keeps rubbing up against things in its aquarium, including the decorative pebbles. Scale loss in your fish may be an indication that they are caused by parasites.

One of the symptoms that your fish has infected Ich is if it begins to hide at the bottom of the tank or behind any decorations. You shouldn’t worry if this is your shy fish’s typical behavior, but if it’s not the usual, ich could be the reason. The Ich could cause enough irritation to set off this reaction. If Ich gets into the gills of your fish, it could cause them to have trouble breathing, which would prompt them to swim to the surface to find more oxygen. 

How contagious is Ich in fish?

Ich is the most common reason for unexpected deaths in fish. If you observe that a significant number of your fish have died in a relatively short amount of time, there is probably a parasite involved. Ich can have a fatality rate of one hundred percent if it is not treated. Your fish will die from Ich in around 5–7 days. If you look for it, diagnose the root cause, and treat it, you can be well quickly. 

How fast can fish get Ich?

The skin of the fish is where the parasites complete their life cycle.

The mature parasites, known as Trophont, then depart the fish after being infected by Ich. After then, Trophont will create tomites. The Trophont then explodes, and a swarm of tomites is let out. After this, tomites burrow through the fish’s skin, which begins the process all over again.

How do I clean my tank after Ich?

I suggest at first you should empty the fish tank and refill it. Turn on the filters for the fish tank and add enough household ammonia to feed the biological filter such that the ammonia level reads 0.5 ppm in the ammonia meter. Raise the fish aquarium water temperature to 75 degrees Fahrenheit. Let the fish tank run for around 10 days. If there are Ich parasites left in the tank, they will be unable to find a host and will die. Similarly, any eggs will hatch and the parasites will die off. 

The biological filter in your fish tank will be destroyed if you use chlorine bleach to sterilize the water. Then you will have to repeat the nitrogen cycle, and either wait two months until the fish tank stabilizes or sacrifice more fish to ammonia and nitrite and risk rekindling an Ich outbreak all over again. 

You should continue to check the water quality twice a week for the first week, and then once a week after that. The Ich problem shouldn’t reappear if you keep the aquarium water in good condition.

Conclusion

As Ich is the most common and widespread disease in fish, there are many ways for them to get it. Even though there is no sure way to stop Ich, you can take some steps to make it less likely that it will spread.

To help stop the spread of Ich, all new fish, invertebrates, decorations, plants, and equipment should be kept in a separate tank with separate equipment for four to six weeks. At higher temperatures, the quarantine period will be a little shorter. Do not change the ideal temperature range for your fish to cut down on your quarantine time. This can make your fish feel stressed and make them more likely to get sick or get parasites. Ich can be stopped by making sure your fish are healthy and have a strong immune system.

A vaccine is the best way to keep fish from getting Ich. There isn’t a vaccine that can be bought yet, but scientists are looking for proteins that could be used to make a vaccine in the future. 

FAQ

Can humans get sick from fish?

I have seen that, just like any other animal, the fish that humans eat could have bacteria and viruses that could hurt them. These bacteria can also get into the water where fish live and swim. Even though keeping fish puts you at a small risk of getting sick because of the water they live in, this is very rare. 

When handling a fish, you might get small cuts or irritations on your skin that could let bacteria in. There are a lot of diseases that can be passed from fish to humans in places where fish are kept or traded. 

Can I feed my fish while treating Ich?

If they are eating, then you should continue to feed them as you normally would. If you are concerned, then you should only give them food once each day. If during treatment the fish stop eating, one of two things has happened, either you have given the fish an excessive amount of the chemical, or the fish are infected with the white spot parasite to a very severe degree.

Can you see Ich on glass?

No Ich does not appear anyplace else on the aquarium outside the fish itself, including on the glass or other surfaces. This time once more Ich can only be seen on the fish themselves. On either the glass or the pebbles, its presence cannot be noticed.

Will fish survive Ich?

Ans. If nothing is done to treat ich, it will eventually kill your fish and spread to others, resulting in the death of a large number of fish. Ich stays in fish for about five to seven days, especially when the water temperature is warm. To avoid this, you should treat infected fish with ich as soon as you notice them. To completely get rid of the parasite from the sick fish, you should continue the treatment for five days to a week.

Can ich live in the filter?

If you treat it effectively, there is great hope that ich won’t return. After the disease has been effectively treated, you do not need to remove any of your existing filtration systems nor do you need to replace any of them. If the treatment was successful, it will have eliminated the parasite from every part of the tank, including the filter, and there should be no trace of it left.

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