Fish ick is the most common cause of fish deaths to diseases.  Its full name is Ichthyophthirius multifiliis.  Many people simply call it ick, or ich. Some others call it fish white spot disease because the most identifiable trait of ick is white spots on the fish.

Ich is highly contagious.  One fish infected with ick will be more than likely to containment the whole tank.  If we do nothing, all fish in the same tank will eventually die.

What is Ick (ich)?

Ick is an external parasite in the water.  It uses fish as hosts.  They feed on the bodily fluids and the flesh of the fish.  One of the major symptoms is white spots on the fish.  It is why some people call it Fish White Spot Disease.

 

Fish Ick has three stages in its life cycle

Free-Swimming ick – Tomites

When fish ick parasites are free-swimming, they are tomites.  The ick tomites are too small to see with naked eyes.  They will keep swimming in the water in an attempt to find a host fish.

In the wild, there is so much water.  Most free-swimming ick parasites might never find a host fish.  In a closed system such as a fish tank, all of them they will more than likely find their targets.

Ick Attached to the fish – Theront

Once the free-swimming tomites find a host fish, they will attach themselves to it. They will form a hard shell around themselves and turn into a cyst.  Fish’s immune response will also attempt to wall off the ick parasite as it is a foreign object.  It will make the cyst grow thicker.  Eventually, the cyst becomes visible to our eyes.  It is when we see the white spots on fish, and it is the only stage we can notice the existence of ick parasites.

When there are a lot of ick parasites attached to the fish, the infected fish might look like full of tiny white lumps, or full of salt.

In this stage, the ich parasites live on the bodily fluids of fish.  It causes the fish extreme discomfort.  Think about mosquito bites to us.  It is very itchy.  We can often see fish scratch against objects in the fish tank because they have no hands.

In this stage, ick parasite is immune to most treatment. Because the cyst protects it and the fish skin wall around it.  On the other hand, no amount of scratch by fish will get rid of it.

Dormant Ick – trophont

When the ick parasites in the stage of Theront become mature, they will bust out of the cyst and fall to the bottom of the fish tank.  In this stage, they are trophont or trophozoite.

The trophont lay dormant at the bottom of the fish tank.  It is the reproduction period.   In the trophont, ick will keep multiplying.  It won’t be long before the trophonts release hundreds of free-swimming tomites and continue their life cycle.

How did fish die to ick?

Secondary Infection

Fish often do not die to ich parasites directly.  The itchy caused by the ick parasites will usually result in fish scratching against objects.  As a result, some fish might injure themselves.  The open wounds of fish will produce the opportunity for bacterial infection.  The secondary infect is what kills the fish most often during an ick outbreak.

Suffocation

Another scenario is when the ick parasites attached to the fish’s gills.  The gills to fish is like lungs to us.  When the ick parasites damage the gill too much, the fish will have a hard time to breath and suffocate.

Fish Ich Treatment

During the three stages of ick parasites, they are the most invulnerable as theronts in the cyst.  The best time window for treatment is when they are free-swimming tomites.

There are a lot of fish ick medications on the market that can kill the ick in their free-swimming stage.  Some are more effective than others. Many ick medications can be hard to the fish or even kill them.  Some meds can damage the good bacteria colony in the filtration to interfere with the aquarium nitrogen cycle.  Some others can kill the shrimp, snail, scaleless fish, as well as the aquatic plants in the fish tank.

So before we begin on selecting any fish ick medication, we need to look at alternatives.

The Fish Ich Heat Treatment

Fish Ick Hates Warm Water

One natural weakness of the ick parasite is the high temperature.  Most strains of ick parasites will stop reproduction in warm water temperature.  Let’s take advantage of it.

To start the fish ick heat treatment, we must first have an adjustable aquarium heater.

Raise the Water Temperature to 86F+

The process of heat treatment is quite simple.  Just turn up the aquarium heater slowly.  Let the temperature raise 2F each hour until it reaches 86F.

While the average life cycle of ick parasite can last 3 to 6 weeks, they will live for only a week or two at most under high water temperature.  In the water of 86F+, ick life cycle will speed up significantly.  At the same time, they can’t reproduce when it is too warm.  By the time the ick parasites matures and fall off the fish without any offspring, it is the end of the cycle.  There will be no more free-swimming ick tomites to start it over.

Fish Ick Heat Treatment Takes Time

To make the heat treatment work, it must last at least ten days or more.  Ideally, continue the heat treatment for another week after no more sign of white spots.  During the heat treatment, you might also want to use a gravel vacuum to clean the bottom of the fish tank extensively.  It will remove a lot of ick trophont which will further reduce the number of ick parasites in the fish tank.

Only the rare strain of ick parasites can reproduce in 86F+ water temperature.  In most circumstances, the heat treatment should work and stop the ick in total two weeks.

Fish Ick Medications

If somehow you are so unlucky and got the rare ick strain, you might want to fall back to the medication treatment.  Some mild but effective ick meds are

Fish Ich Treatment with Medications

Kordon Rid Ick Plus

Formally known as Rid Ick+.  Rid Ich Plus uses formaldehyde and malachite green in its ingredient.  It is effective against external parasites like ick.  It will not affect biological filtration when following the instructions.

Hikari Ick-X

Ick-X is a fish medicine from Hikari. Specialized in dealing with various external parasites such as ick, velvet.

SeaChem Paraguard

Paraguard is a broad medication from SeaChem.  It is relatively easy on the fish, as well as on the filtration.  It can treat many fish bacterial, fungal, viral, and parasitic diseases.  SeaChem recommends to use it for all new fish just to make sure.  They also recommend removing invertebrates like shrimp and snails.  Scaleless fish might also be sensitive to it.

SeaChem MetroPlex

Formally known as Metronidazole.  SeaChem changed the name of their Metronidazole product to MetroPlex.  Like with all their products, they added “Plex” to it.  MetroPlex has 70% metronidazole.  Metronidazole is an antibiotic and antiprotozoal.  It can treat some bacterial infection as well as parasites.  Product direction says it is not safe for invertebrates.  So if you have snails and shrimp, do not use it or remove them before using.

SeaChem Cupramine

Cupramine is one of the stronger medications because it is a copper based product.  Like all copper-based product, it will kill all shrimp and snails.  On the other hand, it is highly effective against all external parasites.

Fritz CopperSafe

CopperSafe is another proven working copper-based ick medication. Once again, do not use it in the tank with shrimp and snails.  It is hard on the fish as well as the plants and filtration.  CopperSafe is not so safe, but it gets the job done.

Some medications will also wipe out the good bacteria in the filtration system and thus cause ammonia/nitrite spike.  Use fish medication only as the last solution.  Start with something mild.

Only Use one single medication at a time

Some medications are not compatible.  Unless the manufacturer specified, do not use any two of them together at the same time.

Remove Activated Carbon

If you have activated carbon in your filter system, you must remove it during the treatment.  Activated carbon is known to absorb medications.  You can return it to the filter after the treatment.  It will help eliminate the leftover medicines in the water.

Since the ick parasites are only vulnerable in their free-swimming stage, speed up their life cycle can have them reach free-swimming stage quicker.  As a result, it shortens the time required for the treatment.  Raise the water temperature speed up ick life cycle considerably.  So combine the heat treatment and with a mild medication can be the fastest cure to fish ick.

Treat the entire tank if there is the sign of ick

If somehow you are unlucky enough to bring home ick, you need to treat the whole tank instead of just the fish you saw with white spots.  There is no telling if a fish has white spots under its gills.  Better safe than sorry.  Or the ick parasites will come back just as you think you have eradicated it.

Fish Ick Prevention

Contrary to popular belief, ick parasites do not appear out of thin air, or water for that matter.  A lot of people believe ich exist in all water sources.  It is false.  You either have ick parasites in your fish tank, or you do not.  If there is ick, you will see the white spots within a few weeks because of the life cycle of ick.  The same thing goes the other way around.  If you do not see any white spots in several weeks, there is no ick at all.

If you have a tank of ick-free fish, they will never get ick until you bring the parasites to the tank somehow.  It is why the prevention is critical.

Only Bring Home Fish From a Clean Source

To prevent ick get into your fish tank, you must be careful about every new fish you bring home.  When you buy new fish, make sure there is no white spot on any fish in the store.  Most fish stores have centralized filtration system connected to all tanks.  A single fish with the sign of ick is highly likely to have other fish infected as well.  Staff in the pet stores are also likely to use the same toolset for fish tank maintenance, which increases the chance for cross-contamination.  Avoid buying fish from any of these tanks if you see a single white spot on a single fish.  Otherwise, you are gambling your luck.

Use a Quarantine Tank

As mentioned earlier, ick parasites can attach themselves to the fish gills.  In this case, white spots are hiding from our view.  To make sure a new fish is parasite free, you need a quarantine tank for it.  It should take no more than two weeks for any white spot to appear on the outside of the fish if there is ick.  If not, then the fish is truly ick-free.  You must also have a separate set of gravel vacuum and fishnet for the quarantine tank to prevent the cross-contamination.

Never let the water from another tank into yours

When you introduce new fish, shrimp, snail, aquatic plants, or even decorations into your aquarium, make sure you do not let the water come with them into your tank.  It might contain free-swimming ick tomits, or dormant trophont.  Ditch the water from other sources.  Wash the plants and decoration, and even your hands if you plan to make contact with the water in your fish tank.

Fish Ick prevention is just important as the ich treatment.  If you prevent ick from getting into your fish tank, you do not have to deal with it.

Enhance Fish Overall Health

Some people believe a healthy fish immune system can prevent fish from getting ick.  It is false.  Just like a healthy person will not stop mosquito bites.  Fish ick parasites are external. Thus their ability to attaching to fish does not change whether or not the fish is healthy.  A healthy and strong immune system will not help fish from getting ick.  No fish is safe from ick as long as it is already in the tank.  It is just the matter of luck which fish get the most parasites.

However, with a healthy immune system, the healthy fish will have much better chance to not die of the secondary infection.  As a result, the healthy fish will more likely to survive an ick outbreak if a treatment is underway.  Likewise, if the fish is weak, its chance of survival is less than ideal.  During the ick treatment, it is essential to keep the aquarium water quality high and give the fish a high-quality diet without overfeeding.