Here is something that I added to an old thread about ICH. It is quite lengthy but lots of good info.
Here is some info that may be useful. I notice that a lot of hobbyist out there are misinformed when it comes to Ich, its treatments and what causes the outbreak. Once Ich is killed in the tank, it is GONE. The only thing that brings it back is an infected fish, (carrier) this fish spreads it around the tank and the Ich looks for a host. If the parasite does not find a host, it will soon die off.
Please read the info below in its entirety. There is a lot of good info regarding Ich, what causes it, and how to remove it. Good luck.
Ich
IT just sounds bad doesn?t it?
This parasite is one of the most common enemies of aquarium hobbyists. Therefore It is also one of the subjects that seems to be most prevalent for myths and confusion. Ich is not difficult, nor is it a true long-term problem, if understood and treated properly. First I will discuss the life cycle of ich, How to treat it, why and how these methods will work for sure, and then the more common myths that are constantly thrown around the hobby. As you read through the treatment section, if something seems to be missed or contradictory from what you have heard, check the common myth section. By all means feel free to PM me with information questions, or debate. As always I try to continually learn, and do not consider myself an all knowing authority. Any additional information I received will be researched and posted.
Diagnosis:
Ich appears on the fish as white spots. They tend to appear raised and are fairly uniform. The fish gains the appearance of having salt grains all over it. You will seldom see ich larger than a grain of salt. Remember this is a single celled organism. This is the outward visible sign of ich once it is established. There are many other more subtle signs that can help you catch it early.
Know your fish, know their behavior. Stress is always indicated by your fish. Clamped fins, abnormal swimming habits etc. these signs are common to many ailments, but the sooner you recognize that there is a problem, the more time you have to find out what you are dealing with.
Gill flashing or scraping. This is the fish reaction to gill irritation. Although there are several possible causes, Ich is the first thing I look for when I see a fish flash against the d?cor or substrate. Only in tanks that I know are ich free do I rule it out, and look for other causes first.
Understanding Ich:
If you fully understand how ich lives, then it is easy to understand how to kill it. Ich is a parasite, which requires a host to live. Fish are the host.
Ich has three life stages. The first stage is the trophont stage, this is the feeding and growth stage of ich. It embeds on your fish, and essentially breaks down the cells around it and absorbs them. The fish?s natural immune defenses will protect the trophont by encasing it with thickened skin and slime coat. It will grow until it reaches roughly the size and appearance of a grain of salt. At which time it sheds it?s cilia, drops off of the fish, finds a home in the substrate and develops an outer ?shell? this shell is virtually impenetrable, and therefore ich is still protected through the second stage of life.
The second stage is the Tomont stage in which it lays in the substrate and begins multiplying. It will divide as much as 2000 times inside it?s protective shell, but does not feed during this stage. After it has divided the hundreds of new ich parasites essentially ?hatch ? and sprout cilia. The free swimmers are called theronts. They swim around trying to find a host (fish). If they find one they attach and begin the trophont stage all over again. During this free swimming stage, ich is vulnerable to medication and other treatments. Furthermore it will die quickly if it does not find a host.
Time frames for each stage are extremely dependant on temperature. Higher temperatures speed up the life cycle dramatically. It may take ich several weeks to go through all three stages in a cool pond, while at 80*f + it will go through all stages in a matter of a few days to a week.
Treatment of ICH.
One of the reasons so many myths, surround this parasite is that treatment is mis-understood by many people.
Treatment must be maintained, for whatever time it takes to catch all parasites in the free swimming stage. It is vitally important to understand how ich lives in order to treat it properly and completely irradicate it.
Many recommended treatments are either not maintained for long enough time, or not a surefire treatment. There are many methods that ?might? kill it, but can?t be guaranteed. A method that isn?t completely sure may be a big helper in the battle, but should not be used as a complete treatment IMO. Treatment must be maintained long enough to ensure that all ich is dead, it only takes one free swimmer to find a host and completely infect a tank again. Above 82* F, 3 days is actually enough time after the last trophont falls off of your fish. I always recommend, as do many people, extending treatment a minimum of one week after all signs of ich are gone. That way if you happened to miss seeing one on the fish, you still get the job done. 2 weeks would be extreme overkill, but then some people are happier with extreme overkill.
At the first sign of ich in a tank, you should begin treatment. Mark your calendar, if you don?t want to go through treatment repeatedly. ICH is fully protected while on your fish, and while in the substrate. It is vulnerable to treatment only during the few hours of it?s free swimming stage while it locates a host. With this in mind, when the ich spots are gone from your fish, it needs to be understood that you have not yet begun to eliminate ich. Treatment should begin immediately to prevent further infestation on the fish, But It will do nothing to the parasites already on your fish. Furthermore if you stop treatment after the fish look better, you are shooting yourself in the foot, and inevitably will need to treat again at some future point. Do it right the first time and put this little bug behind you.
Tank Temperature:
Since we have already established that at higher temps the life cycle of ICH runs faster, one of the best things that can be done to help treatment is to elevate temperatures. Any temperature elevation will help speed things up. Temperatures at or above 86*F are generally considered to be fatal to ich. I have read a couple of articles that cite strains of ich surviving temperatures as high as 90*, but this is very rare. So if you are comfortable with 86* go to that point, if you aren?t at least go to 82-84*. Remember what type of fish you have when considering how high to go. Warmer water does not carry oxygen as well as cool water. Fish that prefer high O2 levels, will be more affected by higher temperature. Take precautions such as lowering the tank water level to increase splash, or raising the spray bars above the water line. If you have good circulation, high O2 levels are not difficult to achieve. Speeding up the life cycle does many things to help us and our fish. First and foremost it gets the parasites off of the fish quicker. Once attached they will be on the fish until they have grown and are ready to multiply. They will cause irritation and stress for as long as they are there so the faster we make them grow the more we help our fish.
Although 86*F is usually fatal to ICH, I personally do not trust elevated temperatures alone to kill it off. If there is a cold spot in the tank, anywhere, there is a chance of survival for the parasite. I consider heat a very good helper in the fight, with the added bonus of being fatal, but don?t consider it a surefire method.
If you have the capability of guaranteeing that all water in the system stays above 86*F then you might consider this a surefire method (Too many possible variables for me). If you try this and don?t kill the ich, then you have accelerated the life cycle of the parasite without keeping it off your fish. This to me would be a dangerous situation.
Temperature should be raised 1-2 degrees per hour at the most until the desired temperature is reached. Drastic or rapid temp changes can be stressful to your fish.
Surefire treatment Methods:
There are two things that will kill the parasite without fail, and with minimal risk/ stress to your fish and tank.
#1. Salt added to the water. Salt will kill ich. Just as meds will. The dosage needed for this is 1-3 teaspoons per actual gallon of water. One strain of Ich has been reported to withstand as much as 5 parts per thousand of salt* so do not rely on light salt dosage to be 100% effective. Most strains will succumb to low levels of salt though
My personal recommendation is 2 tsp. per gallon as a target. This gives me a good solid level with a 1 tsp. per gallon buffer zone in both directions. In other words I can be 1 tsp. per gallon higher than I think I am and my fish should be OK, or I can be 1 tsp. per gallon lower than I think I am and my ich will still die. Many people do quite well with 1 teaspoon per gallon but I don?t like variables so I go higher. This buffer zone is more necessary with hobbyists who don?t know the actual (vs. estimated) water volume of their tank.
To add salt, mix it in small volumes and add to your tank. It is not recommended to dump salt in directly as a solid. My method is to mix it with a bucket of tank water and siphon it into my filter with a ? airline. This ensures it is mixed, and adds it slowly to a high flow area to be further mixed as it enters the tank. I add ? tsp. per gallon once an hour for four hours. This brings me to a level of 1 tsp. per gallon in four hours. At this level, I am far more relaxed and will generally increase it to 2 tsp. per gallon in ? teaspoon increments every 3-4 hours. I always watch my fish closely for reaction. Once I am above 1 tsp. per gallon, if I see signs of increased stress I will slow things down and allow my fish more time to adjust.
Whatever method you use to add salt is fine, but raise the level slowly and mix it well. It will be easier on your fish to do so. At the end of the planned treatment period, I do not worry about quickly removing the salt, I simply go about my normal weekly maintenance without adding any more salt, and eventually it will all be gone from the tank.
Salt is by far my preferred method of treatment, it is less expensive, far less stressful and every bit as effective as ICH meds. Furthermore it is not affected by organic carbon levels which to me makes it more reliable. Filter carbon will not remove salt from the water so if you are using it you do not need to remove it as you do with meds.
As far as what type of salt, you need NaCl. I use table salt, many folks use pickling or canning salt. Iodized salt has never been harmful to my fish, The levels of iodide and other agents are too minute to be a factor. Freshwater aquarium salt is also NaCl as a rule, but is usually more expensive. The only thing I would caution against would be Marine salt mixes for saltwater tanks as they contain many things unnecessary for the treatment of ich, and stand a good chance of changing water chemistry.
#2. Is a combination of Formalin and malachite green. Most off the shelf ich treatments contain these two agents. Read the ingredients before purchase and see what you are buying. If it is other than these two, Find something with these agents instead
While highly effective, there are a couple of side effects that you should be aware of so if you chose to use these meds, so you can use them as effectively as possible.
The first side effect is quite simply the stress it puts on your fish. If your tank is full of tough easy to keep fish that aren?t highly sensitive to much of anything, then you can easily use these meds without a lot of worry. However, if you have smooth skinned fish, or delicate fish, this becomes a much larger concern. I have found that ich meds even when used at reduced dosage, can be extremely stressful to my catfish. I have used meds on Bala sharks, channel cats, pictus cats, and iridescent sharks, and none of them survived and recovered. This is not to say that meds are always fatal to these fish, but the combination of stresses from ich and meds are very hard on sensitive fish. Furthermore since we have already established that ich needs to be treated for more than the 3-4 days recommended by many meds, your fish will be exposed to these irritants for a long time, or you will not be sure you have killed the ich.
The second side effect is the fact that these meds. React with organic carbons. Therefore if your tank is high in organics, much of the meds are used for something other than killing the parasites. This makes dosages more or less effective in different tanks, and therefore makes it harder to effectively treat with meds. The Easy solution is to vacuum very well and feed very little during treatment. How effective this is depends on the individual and their maintenance practices, IT is definitely something to be aware of.
Malachite green can stain your tank silicone, and for that reason it can also be undesirable. I have not actually had it do this in my tanks, but there are enough reports that I would recommend caution if a green/blue tint is completely undesirable in your tank seams.
As with almost any meds, if you use AC in your filters, remove it during treatment. Activated charcoal will remove the meds from the water.
When the treatment period is complete, water changes and fresh Activated charcoal is the way to get the meds out of the water.
Ok, now we know how ich lives and dies, we can get into all of the other fun info like, myths, and less desirable treatment methods. I will also try to cover all of the Frequently asked questions we see on the boards a lot, and hopefully get most of them. Feel free to PM me with additional questions, and I will include them and responses in following chapters.
Treatments that aren?t desirable, don?t work, or have ?issues?
Copper based treatments:
I?ll hit this one first since all the copper fans out there are ready to have me euthanized about now.
Copper and Copper sulfate treatments will kill ich, and pretty much anything else that is exposed to them at a high enough level. It will kill invertebrates, and at some level or another damage your fish. Copper treatments at the recommended dosage are not highly toxic to fish, and the long term damage is a subject of much debate. However copper can and will stabilize in the tank, it can and most often will remain in your tank, This residual copper can stay for years in some systems, and render your tank unable to keep inverts. This is not an every time automatic permanent problem, but the potential exists. Since there are other less dangerous methods, many people consider it absolutely undesirable. I will not put copper in my tanks for any reason. Aside from the fact that I love my snails, In my way of thinking it makes no sense to take the risk when it is unnecessary. For these reasons, I do not consider Copper a viable treatment for anything. I will concede that it is effective, but it doesn?t go into my tanks and never will.
Potassium Permanganate:
This is an excellent treatment for preventing ich?s introduction, many sources claim it will not do a good job of treating ich once it is on your fish though. It, like meds reacts with organic carbons, but my understanding is that it does so very quickly and therefore does not remain reactive for a long enough period to ensure eradication of ich from an active tank. It is recommended as a dip treatment for plants or other items being added from a tank, which is possibly infected. If you can ensure it stays reactive, it will kill ich, but once again there is a huge variable here that adds a lot of risk. It has to be reactive enough to attack the ich while it is in the free swimming stage.
Vacuuming the substrate, micron filter, UV sterilizers etc.
Once the ich falls off of the fish, the cysts land in the substrate and on many other surfaces in the tank. Vacuuming can remove them, they can be captured in a micron type filter, they can be carried out with water changes while in the free swimming stage or while still suspended in the water column. UV sterilizers will kill any free swimmers that go through them as well. The fact is none of these methods are surefire. They can all be counted on to reduce the number of parasites, but the cannot be counted on to eliminate them entirely. I would not recommend buying a UV sterilizer, or micron filter for ich. If you already have one or have other more sensible reasons to own one then using them won?t hurt, and will most likely help you with the battle. I highly recommend gravel vacuuming during treatment. The less parasites that remain the better the chance of complete annihilation by the salt or meds. So anything that can remove them is helpful but should not be considered as a stand alone treatment method. The mere chance of one tomont remaining makes these methods less than acceptable as stand alone treatments.
Salt water bath/ dip for your fish:
Until recently I had never seen this recommended for ich. I have seen this method recommended for other parasites, and have used it effectively. At the time I saw the recommendation, I questioned the source and haven?t heard any additional info. I did some research on my own as well. Ich embeds very deeply, and is protected very well while on the fish. Salt water dips as far as I can find out will not cause it to fall off of the fish. If the dip could somehow draw the ich out of the fishes skin it might help, but nothing I?ve found indicates that this will work. Knowing what we know about this parasite, it is fairly certain that A salt water dip will not kill it while on the fish therefore I consider this method to be ineffective, and not something to use. In addition to the fact that it doesn?t work, it is hard on the fish being dipped. Added stress will further complicate the issue of treatment.
Blackouts:
I occasionally see a blackout recommended for treatment. ICH is not dependant on light for survival, and therefore a blackout will not help kill it. Oodinium (velvet) can be treated this way, but not ICH. Reduced light will However reduce stress on your fish. So if you don?t have plants to maintain, and you are treating your tank. Tun the tank lights off during the treatment. Turning lights off and true blackouts are decidedly different methods, but I imagine confusion about one led to the myth about the other.
Frequently asked questions
Can I use salt with cories, cats, sharks, loaches, Tetra?s pleco?s etc.?
The answer is quite simply yes. Furthermore I would add my opinion that salt should be the preferred method for these fish. My experience is that salt is far far less stressful than malachite and Formalin. Smooth skinned fish and sensitive fish will have enough trouble with the stress of being infected, so the added stress of medication isn?t something you want. Remember that we are talking about a 2-3 week or less treatment not true long term use of salt. These fish will do fine with the levels needed for ich for the small amount of time we are talking about.
Can I use meds with cories, cats, sharks, loaches, Tetra?s pleco?s etc.?
The answer is once again yes. I don?t personally recommend it because I feel that salt is a better less stressful option, However there have been plenty of people who have had success using meds with these fish. Read the instructions carefully, recommended dosages are lighter for sensitive fish. Now with that in mind consider the issue of organics, the need to treat for as much as 2+ weeks, and the chance that ich could survive the meds at a reduced dosage then decide which method you think is better.
Why does the ich seem to be getting worse after I started treatment?
Ich is too small to see with the naked eye through most of it?s life. Only after it is embedded on your fish does it grow to a visible size. Even at elevated temps it can take 4-5 days to reach full size and hatch. So it is not only possible but likely that you will see more ich for the first several days of treatment. This cannot be stopped helped or changed, so awareness is the best we have.
Can I use meds and salt at the same time:
This is kind of a loaded question. Salt and meds will not effect each other, but the combined stress is not a good thing for your fish. And since both will accomplish the same thing without the help of the other it is not necessary to put your fish through the stress of both at once. I would not recommend it at all. People have done it, but I don?t see any sense in it personally.
What about water changes:
You will be here a long time before you ever see me recommend less water changes for any reason. Do as many water changes as you want during treatment. It will help reduce organics, keep your tank stable, and help comfort your fish if done properly. As far as meds or salt you will have to replace what you remove. With meds, follow the manufacturers recommendations, with salt just add whatever your target level is to the change water. For instance if you have 2 tsp. per gallon in the tank, and you change 10 gallons of water then add 20 teaspoons to the change water as it goes back in. the level will remain the same. Evaporation should not be a factor , It is a fact that evaporation will change concentrations, but the change will be minimal and trivial for the period it takes to treat. Remember this is short term in a real time sense.
Will salt kill my snails, shrimp, and plants?
I know for a fact that pond snails, ramshorns, and MTS?s will not even notice the salt.
I am not a shrimp expert, but have not heard any horror stories of salt use with shrimp, and many shrimp will live in brackish water, so it shouldn?t be an issue. If you are keeping particularly delicate or rare species, I would ask the experts before using salt or meds.
As far as plants, I am not a plant guru at all yet. I have used salt with plants in the tank, and have had no trouble myself. The plants I have are reasonably tough, easy care plants, so Delicate plants may be a different story. I have seen so many conflicting reports on salt and plants that I hesitate to take a steady stance here. I do know that long term salt use is not good for most freshwater plants. But short term I wouldn?t hesitate to use it in my tanks with my plants. Once again I would defer this to the plant experts if you have rare or particularly delicate plants.
Why do I still have ich after weeks of treatment?
This is a tough one for us to answer and see on the boards, and seldom do we see it. There are many different strains of ich, many of them are tough little critters. There are also many variables in your tank that we do not know about. If you continue treatment for a full week with elevated temperatures and no sign of ich on your fish, the life cycle dictates that it is gone. Find the variable, or the missed clue. I do not believe in the magical appearance or survival of life forms in my tank. So when things don?t work as they should I look for the true reason with an understanding of what I?m dealing with. On this same vein, many folks mistake secondary infections for continuation of ich. Make sure your diagnosis is correct. Many of us have mis-diagnosed things. It goes with the territory.
ICH is gone but now my fish have something else:
Secondary infections are not uncommon especially with severe outbreaks. Remember the ich attacked and damaged your fish. Unlike ICH, many bacterial and fungal life forms are in your tank at all times waiting for an opportunity to attack your fish. Weakened damaged fish are susceptible to these infections and will need to be treated. For this I highly recommend moving the fish in question to a hospital tank. Then you can continue the ich treatment in your main tank without the worry of added medicinal stress while treating for fungus or bacteria.
I treated for ich but my fish died anyhow !!
I hate to hear this, but it does happen. As with many problems we face in our tanks, we do the best we can. Sometimes a fish is too weak, or an outbreak too big for recovery. Sometimes the stress is more than a particular fish can survive. And sometimes there is some other underlying issue that stressed or weakened the fish and allowed it to get ich in the first place. In this case, ich can often hide the other issue. Because we see the signs of stress, and we think it is all due to the ich. Any time we take on a nasty in our tanks, we have the potential to lose. This is not as common with ich as some other issues, but it still happens all too often. For many years, I would have advised euthanizing any Pictus that contracted ich, because I had never been able to get one to survive. I learned more about the enemy, and tried new ideas with confidence. And today ICH does not scare me I have no doubts that I have a good chance of success with any fish I ever have to treat again. But that does not mean I believe I could never lose another battle with ich either.
I already started treatment, can I switch from meds to salt or vice versa?
Yes if you want to go to the trouble. My usual way of thinking would be to stick with what you started unless there is some good reason to change. Reasons for me would include excessive stress signs from my fish, can?t afford any more medication, don?t want to stain my silicone or something along that line. I would begin reducing one while raising the other so they overlap just a bit. What you don?t want to do is give the ich a chance at getting through your treatment and attaching to your fish. If I were to undertake a switch, I would add my carbon to my filter and immediately begin raising the salt level until I got to one tsp. per gallon. Then do a water change to reduce meds further then raise the salt level on up to 2 tsp. Please understand this method is purely speculation on how I would do it and has not been tested by me.
Why do some of my fish have ich and others don?t
This is very common. Different species and even different individual fish respond differently to the forces around them. Fish with heavy scales armor and slime coat are naturally resistive to ich, other fish seem to attract ich from across the room. In my Experience, if you have a pictus a channel cat, or a Bala shark in a tank with ich you will see an outbreak. No matter how healthy and happy these fish are they will get ich. I have never kept clown loaches, but have heard from many that they are much the same in this regard. On the flip side fish like the Jack Dempsey are ideal carriers. They seldom succumb to a visible outbreak, so ich will go unnoticed on them for extended periods. Young Oscars with their velvety scales are also very susceptible. The last time I had an outbreak, I am fairly sure my Dempsey brought in the ich, he started flashing soon after his arrival home, and within a few day my pictus was covered head to toe. Nothing in the tank except the pictus did any more than flash occasionally, I learned a hard lesson about quarantining new fish that week.
Should move the infected fish to a q-tank and treat there ?
Once ich is in your tank the answer would be no. removal of a severely stressed or infected fish for separate treatment is not a bad thing, In many cases a badly infected delicate fish can benefit from isolation. but the main tank will still need to be treated due to the way ich lives and hides. Once in a tank it generally stays there until it is killed or can?t find a host. It is not uncommon for people to remove a fish cure it, and then add it back to their main tank only to have it immediately break out with ich trophonts again. Quarantining before introduction is great, after introduction is generally a waste of effort.
MY LFS?s tank had ICH should I avoid that store from now on?
In order to be fair to the LFS?s of the world, it should be noted that it is virtually impossible to move and house the mass volume of fish that they do and prevent disease introduction. I evaluate an LFS based on what they sell and on frequency of a problem. If they recognize, treat and refuse to sell sick fish they have done the best they can in my book. When I see an infected tank that isn?t marked, I generally bring it to an employees attention, if they treat and mark the tank, I will consider doing business with them, if they ignore the issue and continue to sell those fish, I don?t go back. The LFS that I buy all of my livestock from will hold fish that are being treated for their customers, but will not allow them to leave the store until one full week after the treatment is finished. This gives them time to evaluate the fish and ensure that they are well.
Prevention:
Quarantine tanks:
It is simply impossible to over emphasize this idea. I didn?t use to use q-tanks for many years, and can pretty much rattle off any excuse you?ve ever heard or thought of to not use them. Bottom line is the excuses don?t hold water, but anything that does hold water can be your q-tank. Find something and use it to protect your fish and tank from infestations. Observe the fish in quarantine for several weeks, and if there is any sign of a problem, find it treat it, and give them several more weeks before adding them to your main tank. I?ve been burnt enough times to make this a standard policy.
Mr. Ricketts can count me Among his convertees in this world of q-tanks, If you bring something home and put it in your tank right away, you have run the risk of re-introducing ich and who knows what else. It could go literally years unnoticed and then one day when things go wrong you are under attack again. Don?t take the risk. If you even think your new fish has ich treat the q-tank accordingly.
Potassium permanganate Dips:
This is considered the stuff to use for d?cor or plants coming from another tank. KMNO4 can be harmful to delicate plants according to much of my research, but it is also cited at being effective in very low concentrations, it is of course really unnecessary if you quarantine your plants.
Drying things out
The tomonts and free swimmers cannot survive being dried out so as far as d?cor, nets gravel, or any other inanimate items involved simply letting it dry out good will prevent cross contamination and re-introduction. I keep lots of nets, and allow my nets to dry out completely whenever they are used to net a new fish coming home. An ounce of prevention?..
No host no life
In the case where a fish population was decimated, Many people ask how to decontaminate the tank. It?s very simple with ich. When there is no host it dies off permanently. Once again in case it was missed earlier ICH has no dormant stage, so 2 weeks without fish in the tank will irradicate it. Elevated temps will speed it up and higher temps (above 86*F) will put the double whammy on it. However the fact still remains, all it takes is time. It will starve to death quickly without fish.
MYTHS !!!!!!!!!!!
ICH IS ALWAYS IN YOUR AQUARIUM:
This is my absolute favorite one. And probably the most common one. There are many reasons for this myth, but all of them can be defined and eliminated by understanding the life cycle of the parasite in question. ICH must have a host to live. It does not have a dormant stage, it cannot survive in a tank without fish for more than a few days at tropical tank temperatures. Even in very cool water it is limited to 1-2 weeks at the absolute most. ICH does a good job of hiding from hobbyists who don?t know what to look for. It also does a great job of sneaking into your tank. It cannot spontaneously appear, and it cannot live without a host.
Many fish are highly resistive to ich, however the gill area of a fish is not protected in the same manner as their skin. It only takes one free swimmer to attach to the gill to continue the life cycle and allow ich to remain in the tank. Like many parasites ich prefers the gills. This makes a lot of sense, given that the gills are full of food, they are reasonably soft, and they are not protected with scales and slime coat. ICH cannot be seen when on the gills however a fish with irritation will flash and scrape their gills. This sign should never be ignored. ICH is not the only thing that will cause a fish to flash or scrape, but when a fish does this there is almost always something amiss so careful observation and diagnosis is in order
ICH is caused by temperature drops:
This myth has a little more basis simply by the fact that temperature drops can and often do lead to ich outbreaks. The facts are that fish which are normally able to fight off ich, have weakened immune systems in colder temperatures. Almost any stressful situation can produce the same result. ICH is caused by parasites that are already in the tank attacking a host that for whatever reason is unable to fight them off at the moment of attack.
ICH can remain dormant and hidden in your tank:
Very clearly not true. Ich does not have a dormant stage, and cannot go dormant. This myth was essentially created by the fact that people could not explain the existence of ich in a tank. The fact is that whether or not they had a visible outbreak, they did have ich actively going through the stages of life in their tank.
ICH can live on plants:
I would call this a half truth. Plants can be a vector for introducing ich in a tank. Ich will settle on many surfaces during the tomite stage. If you buy a plant from a tank with ich, and bring it home and plop it in your tank, you could very easily add ich to your tank. Then the ich hides for a year until you heater breaks your fish get covered with white spots, and you start to believe the spontaneous generation myth. Dip your plants in Potassium permanganate, or better yet quarantine them for a minimum of 3 days. I?d do the same with snails or anything else from another tank. Tank water from the LFS has a good likelihood of having free swimmers in it. Thus the advice of never dumping their water in your tank.
*Information borrowed from the Skeptical aquarist website citing a study by the Southern Regional Aquaculture Center
***Special thanks to all of the many people who have contributed information, written articles, and studied this nasty little parasite to make it easier for us to kill it.
