Ich is a parasitic infection that is common in freshwater aquarium fish. Fish usually get this infection after experiencing stress. It may also occur if hobbyists fail to quarantine their new fish or plants.
Ich is often fatal. Many hobbyists stop treatment early, failing to kill the parasites.
Ich is invisible for most of its life, fooling caretakers into thinking it’s no longer there. Reinfection occurs when hobbyists stop treatment early.
Fortunately, treatment is very effective as long as hobbyists follow the proper instructions. Always follow the directions on medications, and NEVER stop treatment early.
What Is Ich?
Ich, or white spot disease, is a type of parasite called Ichthyophthirius multifiliis. The organisms are ectoparasites, meaning they live on the outside of their host’s body.
These parasites live in waters worldwide and can affect all freshwater fish species. The marine equivalent is “marine ich” or Cryptocaryon irritans.
Cilia surround the parasites’ bodies. Cilia are thin, hair-like structures that vibrate and help the parasite move.
Ich is one of the most common problems that freshwater aquarium fish face. Many fish die from ich, though survival is possible with proper treatment.
Ich Has 3 Stages
Like most parasites, ich parasites have three different life stages. They spend some of their life in the environment and other parts in their host.
Trophont (Feeding Stage)
Cysts enclose the parasites during the trophont phase. The cysts appear as small white spots noticeable on the fish’s body.
During this stage, the parasites focus on eating. They continue to grow larger until they break through the cysts and fall to the substrate below.
Tomont (Reproduction Stage)
Tomont parasites attach themselves to the substrate and other items in the aquarium.
Then, the tomont goes through mitosis — the process of splitting itself. By dividing themselves, they create 250 to 2,0000 ciliated parasites called theronts.
Theronts (Free-Swimming Stage)
Mature theront parasites use their cilia to swim through the open water. They search for a host, and when they find one, they penetrate the skin.
After attaching, they grow larger until they become a visible white spot.
Theronts must find a host within 48 hours, or they will die.
The Duration Of The Life Cycle
The life cycle of ich parasites may last for as little as three days or as long as three months.
How long their life cycle lasts depends on the temperature of their environment.
In warmer temperatures — 73.4-75.2°F (23-24°C) — the life cycle lasts only three to eight days.
The lower the temperature, the longer the parasites can live. At 39.2-41°F (4-5°C), the life cycle can last up to three months.
Ich parasites cannot survive in temperatures above 86°F (30°C) or below 35.6°F (2°C).
The Causes Of Ich
The most common cause of ich is stress caused by poor water quality or improper quarantine.
Stress & Poor Water Quality
Poor water quality causes a lot of stress and compromises the fish’s immune system. Weak fish are more susceptible to parasites because their bodies can’t fight them.
Stress may occur due to high ammonia, nitrites, or nitrates. It can also occur due to cold or hot water temperatures or too-strong currents.
Various parasites commonly exist in aquariums without hobbyists ever knowing. As long as the fish is healthy, its body can fight off the parasites, and it never becomes infected.
Stress & Sudden Water Changes
Sudden changes in the water parameters can cause fish stress. Avoid drastically changing the temperature or pH in the tank. Make changes slowly over several days.
Stress & Bad Tank Mates
Avoid tank mates that will cause bettas stress. Fighting amongst fish can cause stress and injury, making them susceptible to ick.
Improper Quarantine
Ich occurs in fish tanks because hobbyists don’t quarantine their new fish for long enough, or at all.
Placing new fish directly in the main tank is not a good idea. They may be hosting an illness that isn’t visible at first.
A quarantine period of four to six weeks allows hobbyists to observe their new fish for any problems.
Ich is highly contagious; infected fish can easily transmit it to their new tank mates.
How To Prevent Ich
Ich in betta fish is easily preventable. Keep the fish’s environment healthy and follow quarantine protocols.
- Perform regular water changes and cleanings to keep the tank healthy
- Test the water regularly to ensure the ammonia, nitrite, and nitrate levels stay low
- Test the pH levels to ensure they remain stable and within a safe range
- Check the temperature often to ensure it is warm enough for bettas
- ALWAYS quarantine new fish for at least two weeks before adding them to the main tank
- Quarantine new plants for at least two weeks before adding them to the main tank
- Thoroughly clean used tank items before using them in a new tank
- filters, decorations, heaters, etc.
Ich Symptoms
The easiest way to spot ich is by looking at the betta’s skin, fins, or gills. Ich shows up on the body as tiny, white, salt-like dots.
There may only be a few spots on the fish while the infection is mild. The longer the infection occurs, the more the parasites will reproduce. Highly infected bettas will have white dots all over their bodies.
Ich in betta fish causes symptoms common in other illnesses:
- Lethargy
- Trouble breathing
- Loss of appetite
- Clamped fins
- Cloudy eyes
- Flashing (rubbing against decor to relieve itchiness)
- Scale loss
- Bruising
- Hiding
How To Treat Ich
Betta fish with ich should receive immediate treatment. Treating the infection as soon as possible prevents the infection from spreading.
Treatment lasts for several weeks. It is only effective during the trophont life phase. Current medications in the market have no effect during the tomont or theront stages of life.
The goal is to kill all the free-swimming theronts in the tank. By killing the theronts, hobbyists can prevent reinfection.
Isolate Sick Fish
Many betta fish live in their tanks alone and can receive treatment there. Doing so often reduces the stress the betta is feeling.
Hobbyists may need to move solitary bettas to a hospital tank if their home tank is too big. Sick fish often have trouble moving and swimming to the top for air and food. They may suffocate or starve to death in a too-large tank. Move them to a shallow hospital tank for easy swimming.
Move bettas to a quarantine tank if they live in a community environment.
Treating healthy fish with medications they don’t need can cause stress. It also causes them to build up immunity and makes the medicine less effective if they get sick in the future.
Move all infected fish from a community tank to the hospital tank. Healthy fish can stay in the main tank. Move them to the hospital tank if they begin displaying signs of infection.
What About The Main Tank?
Don’t worry about treating the main tank if it is now empty.
Theronts must find a host within 48 hours, or they will die. Removing organisms from the main tank for about two weeks means all the ich parasites should die.
Afterward, the tank will be free from the parasites, and the healed fish will be safe to return home.
Heavily Filter The Water & Perform Water Changes
One study suggests heavily filtering affected aquarium water. Use diatomaceous earth or membrane filters to kill many of the free-swimming theronts.
The researchers suggest moving the fish to a new, clean aquarium every seven days. Moving the fish helps prevent the theronts from reproducing as quickly.
Hobbyists can achieve the same outcome by doing daily water changes. Ensure the pH and temperature of the changing water stay the same to prevent stressing the fish.
Use a gravel filter to clean the substrate while performing a water change. By cleaning the gravel, hobbyists will get rid of the parasites living there.
DO NOT filter the water with activated carbon, as it removes medication from the water. Remove all activated carbon from the tank during treatment.
Raise The Water Temperature
Ich parasites live shorter lives in warmer water and cannot live above 86°F (30°C).
Slowly raise the tank’s temperature over a few days to shorten the parasites’ lives. Aim for getting the temperature between 81-86°F (27.2-30°C).
Only raise the temperature by 1-2° a day. Raising it more quickly than this can cause fish to go into shock.
Use An Airstone
We recommend adding an airstone to the betta’s tank during treatment. Warmer temperatures hold less oxygen, and many medications also reduce the oxygen content.
Adding an airstone helps maintain the oxygen levels in the tank so the betta won’t struggle to breathe.
Remove Hard Decorations
Infected fish like to rub their bodies on the sides of decorations to relieve their itching. They can rip their fins and bodies by rubbing themselves on decorations too hard.
It’s best to remove decorations made from hard materials during this time.
Leave plants and other soft decorations to help the fish feel safe. Fish won’t heal as well in a completely empty tank because they will feel exposed, which causes stress.
Use Anti-Parasitic Medications
Closely follow the directions on the medication bottle to ensure proper treatment. NEVER stop treatment early, or infection will likely recur.
Simply because the parasites aren’t visible in the water doesn’t mean they aren’t there. Tomonts and theronts aren’t visible to the naked eye.
Formaldehyde
One option is to treat the aquarium with formaldehyde at 25 ppm (about 1 mL per every 10 gallons).
Treat the tank with formaldehyde three times, skipping a day between each dose. Perform a water change of up to 75% four to eight hours after dosing.
Choosing products containing formaldehyde is safer than trying to dose out pure formaldehyde. Products containing formaldehyde are called “formalin.”
Copper Sulfate
Copper sulfate is one of the most effective anti-parasitic medications.
Unfortunately, it is also one of the harshest. Extremely sick bettas may not survive treatment with this medication.
Never use copper-based medications with invertebrates or scaleless fish (like loaches). Copper is toxic to these organisms and will kill them.
Mix Aquarium Salt Into The Water
Consider adding aquarium salt to the tank to promote healing. Follow the directions on the package to know how much to add.
How Long To Treat Fish
Most hobbyists can stop treatment after about ten days. Treatment rarely needs to extend past two weeks.
After Treatment
Continue treating the betta for about five days after all visible signs of ich are gone.
Remember, parasites may be present even if they aren’t visible. Continuing the medication for a few extra days ensures it has had time to kill all the parasites.
Once treatment is over, perform a water change of about 50% to get rid of most of the medication in the tank. Add activated carbon back into the filter, and it will remove the remaining medicines.
Ich Might Not Be Obvious After Fish Death
Research finds that trophonts are not always visible after a fish has died.
Remember that the trophonts exist inside cysts that appear as white spots over the fish’s body.
The parasites exit the cyst and drop to the bottom of the aquarium after the fish dies.
Since the trophonts are not always visible in dead fish, the infection may be able to spread more easily.
Hobbyists unaware of the infection are unlikely to determine the cause of death. They may dismiss death as something else. The infection will continue to spread without antiparasitic treatment.
FAQs
Why Does Ich Keep Coming Back?
Ich that keeps coming back was never truly gone in the first place.
These parasites have three life stages. Medication is only effective during one phase. The parasites are only visible during another.
Many hobbyists don’t know this and stop treatment when the white spots are gone.
Unfortunately, medication is not effective on ich when it is visible.
Stopping medication early allows the parasites to spread.
Is Ich Contagious To Humans?
Humans can’t catch ich from caring for their tanks.
Hobbyists should thoroughly wash their hands after caring for an infected tank. Owners that don’t wash their hands between tanks can transfer the infection from tank to tank.
It’s best to have separate cleaning supplies for each tank for the same reason. Avoid using the same supplies between many tanks (e.g., siphons, sponges, nets, etc.)
Are Fuzzy White Spots A Sign Of Ick?
Fuzzy white spots are not a sign of ich — they are a sign of a fungal or bacterial infection.
Ich is unique in that it looks like small, white salt-like spots. The spots are uniform and do not appear fuzzy.
Large, fuzzy white spots are usually a type of fungus.
