Ich is a relatively prevalent issue for much freshwater fish, including koi and goldfish.

What exactly is Ich?

The Ichthyophthirius multifiliis protozoan, often known as ich or white spot disease, is an external parasite that adheres to your fish’s fins, body, and gills by creating a small white capsule (usually less than 1 mm in diameter).

It slips off the fish after feeding on it and maturing, wraps itself on the ground or other tank surface, and rapidly copies itself.

When the reproduction process is complete, the cyst ruptures, and hundreds of young ich protozoa are released into the water, where they might swim for two to three days until they find a new host to attack.

The sooner you catch and treat the ich, the greater your fish’s chances of recovering completely.

Will Ich kill the koi fish?

Ich does not always kill fish completely. However, it causes a slew of fish problems, leaving them weaker and anxious. The gills are particularly susceptible to Ich invasion. When infected, the gill cells swell and distort. As a result, the gills’ oxygen intake is restricted.

Because of this asphyxia, Ich-infected fish are frequently seen near water inlets or bubblers. To breathe, the fish will seek greater oxygen locations.

The harm extends beyond the gills. Theron’s will attach themselves to every part of the fish’s body they can find. The epithelium and mucous membrane of the fish are also affected when it is linked to the body. This might expose the fish to secondary infections.

This results in a highly stressed fish that is significantly more vulnerable to death for various reasons.

Is it contagious?

If there is an epidemic of Ich in koi, the parasite will spread quickly across the group of koi, infecting every fish in the body of water.

If left untreated, the Ich parasite can kill a large number of fish in a short period. Small fish, like other parasites, are more likely to succumb to a high infestation of Ich rapidly, whereas larger fish will suffer for longer. Because of its rapid reproduction cycle and different life stages, Ich may be a bothersome and chronic disease.

Although little white specks are the tell-tale evidence of ich parasites, koi may also exhibit behavioral signs. These include decreased appetite, swimming alone, hiding beneath shelters, and rubbing against pond objects to scrape the parasites off. Among the symptoms that might be listed are the following:

Symptoms of Koi Ich:

  • Small white specks that resemble sand grains
  • Rubbing against pond items
  • Appetite loss
  • Swimming away from the crowd
  • Hiding behind shelters/at the pond’s bottom Lack of color and dreary look
  • Infections caused by bacteria or viruses (i.e., ulcers)

What causes Ich?

  • Stress: Stress has a significant impact on immune system responses. When fish (humans or any other living thing) are stressed, their immune system is weakened. This is an excellent chance for all kinds of things to infiltrate their body.
  • Stress can be caused by inappropriate mates, bullying, the wrong water parameters, too much light, not enough hiding places, not enough buddies, or too many “friends” for lonely fish. It’s also possible that you’re staring at the tank too much.
  • When fry contract ich, their immune systems are underdeveloped.
  • Newly Introduced Fish: A newly introduced fish is not only agitated but also prone to stress out established occupants. This is an excellent time to introduce a pathogen.
  • Pathogens can enter any surface contaminated in an infected tank, including newly imported plants.

How can I tell if my koi has ich?

A koi with ich seems to have small crystals on its body as if salt was sprinkled on it. We usually see ich on the fins first because there is less slime coat in those locations, and the parasite finds it simpler to target. Other signs may include, as previously noted, loss of appetite, fast breathing, fish rubbing their bodies against surfaces, lethargy, and hiding behavior.

If an external parasite causes your fish, you will notice five spots today and maybe 35 spots tomorrow. However, some fish develop “stress ich,” or stress patches covering the entire body (not just the fins). If you have five spots today and the same number of spots tomorrow with no growth, you may have stress, which does not always respond to the same treatment regimen as shown below.

For example, ich is similar to chickenpox (spots produced by an infectious microorganism). Still, stress is similar to stress acne (which are spots caused by hormones and are not contagious). The chickenpox and stress acne therapies are quite different, yet they are also the same.

Treatments for Ich

There are a lot of parasite treatment alternatives available, but none may be more successful than the Formalin and Malachite Green combination found in Ich-X. (click on this link for treatment details).

At 86 degrees Fahrenheit (30 degrees Celsius), there is some evidence that ich either a.) cannot increase or b.) cannot attach itself. Temperature rises may be a potential strategy for ich eradication without medication if your fish can survive such temperatures (up to 89F or 31C).

It’s worth mentioning, though, that I’ve tried this strategy with varying success. Sometimes ich appears to “correct itself” and dissipate after a few days at this temperature, while other times, it worsens the issue.

If you wish to use this strategy, raise the temperature as high as your fish can tolerate.

If your fish can tolerate temperatures over 86 degrees Fahrenheit, leave the temperature there for four days before lowering it to 86 degrees Fahrenheit for two weeks to ensure they’re all gone. If you discover that it is exacerbating the condition, use another approach listed below.

Garlic boosts the immunological response of numerous species, including fish. Garlic Guard may be added to your fish’s diet a few times each week to improve their immune system and help them fight against ich. However, this approach is probably not suited for severe instances of ich.

In addition, 3 pounds of Pond Salt per 100 gallons of pond water (0.3 percent) can be used to treat Ich, although it will most likely not remove it. Maintain the salt level for a few weeks while monitoring it using a Koi Medic Salinity Meter, and then do a partial water change to minimize the salt content.

API POND SALT Pond Water Salt 4.4-Pound Container (156C)
  • Contains one (1) API POND SALT Pond Water Salt 4.4-Pound Container
  • Promotes fish health and disease recovery with increased electrolytes
  • Improves respiration for fish in pond
Digital Salinity Tester for Salt Water - Waterproof IP67 Salinity Meter with ATC Large Range...
  • Salinity Range: 0~9999ppm/10~200ppt or 0.0-25%, ORAPXI salinity tester has an automatic temperature compensation function(32°F~140°F), which can decrease the error caused by the change of liquid temperature.
  • Wide applications: There are various purposes for the salinity tester. This instrument can not only detect the salt content of edible salt, salt water pool and koi fish pond, but also the salinity of seawater, marine, salt water fish tank salt level testing.
  • Backlit design: There is no need to worry about seeing the displayed value if the light is insufficient. ORAPXI salinity meter features a green backlit LCD to help you see the measurement results clearly in any situation.
Hikari Usa AHK73214 Ich-X for Aquarium, 4-Ounce
  • Hikari ich x 4oz
  • The most widely respected formulation for the treatment of ich
  • Additives & supplements

Applying Ich-X followed by Pond Salt after the last water change is probably the best treatment choice, keeping it around 0.3 to 0.5 percent for a few weeks. In theory, this will destroy the parasite and its life stages. However, Ich is a real pain in the neck, and follow-up therapies are frequently necessary.

If the circumstances that generated the epidemic are not rectified.

When treating Ich, always keep a close eye on the fish and be ready to flush the pond immediately if they look agitated. Also, with any of these treatments, ensure to aerate thoroughly, remove as much organic material as possible, and treat the make-up water with a Water Conditioner.

Finally, if used as prescribed, Ich-X should not harm plants or biofilters, although salt treatments may.

To reduce the impact on the biofilter, add 1 pound of salt per 100 gallons, wait 12 to 24 hours, then add another 1 pound per 100 gallons, wait 12 to 24 hours, then add the last 1 pound per 100 gallons. Most (but not all) plants can withstand 1-1/2 pounds of salt per 100 gallons (0.15 percent), while 3 pounds per 100 gallons may be harmful.

How to Prevent Ich

  1. With a 10-day continuous water temperature of 55 degrees Fahrenheit, it is time to begin spring feeding and restarting your pond.
  2. New fish should be quarantined for four to six weeks (temperature dependent)
  3. For two to four weeks, quarantine new invertebrates that had previously been maintained alongside fish.
  4. Before introducing fresh plants to the tank, quarantine them all (two weeks with no fish)
  5. To keep Ich and other parasites and illnesses out of your aquarium, quarantine any new arrivals, including fish, invertebrates, and plants, in a separate tank with separate equipment for four to six weeks. At higher temperatures, quarantine will be somewhat shorter.
  6. Do not change your fish’s optimal temperature range to reduce the quarantine time. This can stress your fish and leave them vulnerable to various illnesses and parasites.
  7. Quarantine any new plants that have previously been housed with fish. The parasite life cycle will be broken, and the parasite will die off if plants are kept separate from all fish and invertebrates for at least two weeks. A fish must host Ich to complete its life cycle. Because travel and handling may easily harm aquatic plants, use these two weeks to strengthen your plants with some extra fertilizer.
  8. Maintaining adequate water quality and feeding an appropriate food can help your fish’s general health and well-being. Maintain a regular maintenance routine.
  9. I keep a well-kept and balanced pond. Treating the water with an Algae Fix and beneficial bacteria in early spring once the water temperature has reached 55 degrees Fahrenheit for some time, and monitoring the water for ammonia and PH balance. 
  10. Check-in on all of your fish daily and get to know their usual appetites and habits so that you can spot problems promptly. If you feel your fish is ill, call your aquatic veterinarian as soon as possible.

Last update on 2022-09-11 / Affiliate links / Images from Amazon Product Advertising API