A Closer Look at Goldfish Ick – Part 2 (Treatment)

Before reading this post, it would be advisable to read “A Closer Look at Ick – Part 1 (The Life Cycle)”. Several of the terms and concepts mentioned there will be referred to in this post.


Once ick has been discovered in a tank, the first task is to prepare the tank for treatment. If any filters contain activated carbon for chemical filtration, remove it. The activated carbon will remove the medication from the water. UV sterilisers and protein skimmers should also be switched off in order for the treatment to work effectively.

The water in most goldfish tanks is at room temperature (roughly 18 Celsius/65 Fahrenheit), so there is no general requirement for a thermostat. However, using one to gradually increase the water temperature by half a degree celsius every day will reduce the length of treatment. This is because the ick is only treatable during the theront (free swimming) phase of the life cycle. Due to the fact that an increase in temperature speeds up the life cycle, the theront phase will arrive quicker at higher temperatures.

If possible, bring the water temperature up to 26 Celsius (80 Fahrenheit) and the treatment will be over in 10 days. Keeping the temperature low will mean the treatment will need to continue for 6 weeks. One word of caution though – when the ick life cycle takes a week, a new dose of parasitic infection comes round every week. If anything is wrong with the treatment program it could result in heavy infestation, and goldfish dying off quickly.

Finally remove any snails, and check if any aquarium plants present are sensitive to the recommended treatement – malachite green.


Malachite green is a widely available chemical treatment for ick. Other chemicals that can be used are formalin, copper, quinine hydrochloride, methylene blue and sodium chloride. However, non of these are any better than malachite green, which has the advantage of been successfully used to treat ick for many years.

Follow the dosing instructions on the label to the letter, taking care to avoid eye and skin contact. Malachite green leaves a stain on almost everything it touches.

At the ideal temperature, continue the treatment for 10 days. This will ensure that the theront phase of the ick life cycle will have been exposed to the malachite green. During the trophozoite and tomont phases, the chemical will have no effect on the parasites. In both cases they are enclosed in protective cysts that are impervious to any known treatment.

Although the life cycle only takes a week at this temperature, the treatment should go on for 10 days in order to make sure that all traces of ick have been removed.

It is worth noting that the treatment for ick treats the water. When treating the vast majority of goldfish diseases it is the goldfish itself that is treated. However ick can only be killed when it is vulnerable, and that is when it is out in the water.


As is the case with every goldfish illness, prevention is better than cure. Make sure the water is tested regularly, feed the fish a balanced diet, change the water regularly and don’t put too many goldfish in the tank. These measures should be par for the course in every single goldfish tank and pond.

Also, never buy aquarium plants that are in a tank with fish in the pet shop. Tomonts stick to plants, and a single one provides an easy passage for up to 1000 individual parasites.

When bringing a new fish home for the tank, put it in a quarantine tank for whatever length of time the ick life cycle takes at the water temperature of the quarantine tank.

Ick is common and deadly, but following the advice above will save goldfish from the disease, and bring them back to rude health as quickly as possible.

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38 Responses to “A Closer Look at Goldfish Ick – Part 2 (Treatment)”

  1. Kelly Says:

    Help 2 of my goldfish have come up with white spots all over them which is ick. I cant affard any treatment and i dont even know where to get it from. Will they carry on living without the treatment? if not how long will it take for them to die?

  2. admin Says:

    Use ordinary salt. You will need 3 teaspoons of salt for every gallon of tank water. Dissolve it in some water you have removed from the tank, then pour it in to the flow of the pump.

    When you do your weekly water change, top up the salt levels according to how much water you took out.

    To answer your questions, they will probably not survive if you don’t treat them. Hopefully they will not die if you go with the salt treatment.

    Good luck

  3. Kim Says:

    Hi there,

    I noticed that my fish had little white spots on them a while ago and treated them with a White Spot Cure that I bought at the local aquarium shop. I was told that it may take some time for the treatment to work. However, it did nothing even after full course. I went back and got a ‘Tonic’ which apparently is a treatment for a whole host of diseases including ich, fin rot and fungal skin diseases (contains malachite green). I’m midway through the course and one fish has died from what looks like fin rot and the others have suddenly got cloudy eyes, furry fins and have gone off their food. It pretty much happened overnight!! Do you think that treating them with antibiotics will help or maybe the disease has spread too much?

    Any help would be appreciated as I feel a little helpless!



  4. admin Says:

    Sounds a lot like a bad bacterial infection. Your fish seem to have more than one problem, so you need to get on top of the situation quickly. Your next port of call should be a vet.

    If not all of your fish are affected, remove the ones that are to a treatment tank.

  5. Han Says:

    hello, admin. my goldfish has white spot on it gills few days ago and i do twice seawater treatment to remove it. however, the white spot continue appear and now the white spot is gone. what should i do for following prevention?

  6. admin Says:

    As I mentioned in the article, the best prevention is to keep the water clean and the fish healthy.

    However, it may not have been ick. Have a read at this article about sexing goldfish. The spots may have been breeding tubercles on a male goldfish.

    It’s not the right time of year if you are in the northern hemisphere and your fish are in a pond, but entirely possible if they are in an aquarium.

  7. Derek Says:

    I got my son goldfish as he is intrested in my bro-iin law’s tropical fish but these goldfi
    sh started getting white spots now my son is crying all the time because thse fish are dying and i bought more ,but these fish are the same could anyone please help me sort this problem out , even some advice on what ive done wrong and how to solve it .

    Could anyone please give me advice ,is it about my new tank ?

    thanks a lot .Derek

  8. donnetta Says:

    MY GOLD FISH HAS WHITE SPOTS ON THEIR MOUTH I”AM NOT SURE IF IT’s ick but i have changed the water. two of them died. but the other two. and my algea eater are still tyring . the algea eater has white parts of his tail that looks like a mouth on the end of it’s tail. please can you tell me what i need to do i”ve tried ick treatment but it has’nt worked. so now i’am tryin the salt. i have a fifty five gallon tank. not sure how much salt i should use.

  9. Ray Says:

    Hi, can anyone please help me? I have 1 goldfish with ick and two alge eater and one feeder fish, my goldfish is the only one sick so is the rest going to be ok? Also my goldfish is in a bucket right now with salt like stuff on his body so I added one teaspoon of salt and a heater but with no filter or oxegen is he going to get better? And how long do I leave him in their for? If anybody can help I thank you so much

  10. h Says:

    I have 4 fantail goldfish and one of them seems to have clamped fins that look like a diagnostic diagram of ick. this has been going on for around 10 days. the other fish seem to be normal, and my tank is around 2 months old.

    can I treat it with 3 teaspoons of salt for every gallon of tank water as explained above, and for how long. do I have to remove the carbon from the filter during treatment.

    thank you for your help

  11. @$^! Says:

    JUST bought some “feederfish” from my local petstore this weekend and the next day i was sure they were sick, looks to b ick and so far 1 has died,
    learned we are brainwashed to think these fish should only last a few days, they can last 20 yrs, they are just treated badly!
    dont think i can get to a petstore in time to save them 🙁
    going to aqu services to buy any other fish I should have in the 1st place didnt have trouble w them when i had tanks yrs ago in hs.
    dont want to try salt i killed off my fish last time in hs 🙁

  12. paul p Says:

    ray: without oxigen, the fish will die. fish has to have oxigen. derek: no, its not a new tank, if you get a fish with ich, treat it with ich-away by wardley and then 24 hours after treatment, change 50% of the water and then, treat it again 3 days later. then, a week from that, change 100% of the water. glad to help.

  13. GODZILLA Says:

    HI, I have a 15 gallon tank with 2 beautiful goldfishes. One of them is a common and the other is a commet. But recently my cousin wanted me to take care of his 3 commet fishes and I put them in the tank with my fishes. I realised that they had bunch of white spot on them and I remembered that when fish wants to make babies this happens. But surely this was not the case because one of them lost half of its tail. So i removed them from the tank and quarantied those 3 in a small fish bowl no bigger then 1-2 gallon. I aslo added some medication referred by the petstore. My question is that even before I took the fishes from my cousin I noticed that the fishes had this white spots for lets say emm 2-3 months. SO are the fishes going to survive if I keep them in medication?

  14. Nancy Says:

    I had a goldfish-like-carp-like fish for about two/three years which was healthy and lovely until only recently. My sister bought a used fish tank, a 20 gallon one, and went to one of the pet chainstores nearby to buy a few pretty goldfish and some guppies. I decided to let my fish in with hers and recently he has shown signs of ich. One o f her gold fish died and mine looks really sad and unhealthy.

    We went and bought some medication and he still has the fungus all over his body.

    I see that adding salt to the water is an alternative and am curious if I could add some coral as well. We have some lying around and wanted to know if it would harm them by sticking it in. We would like to use it as a preventative measure. My fish is now separate from the others because he is so sick. I will continue to add the ich medication, but would like to learn more about the salt treatment.

  15. Nancy Says:

    Note on the above comment: the coral is not alive, as in it has not been in water as we have never owned saltwater fish; it is old and from long ago traveling.

  16. Jessica Says:

    I have 3 goldfish, and algea eater and a snail in my tank. The goldfish now have ick. Can humans or dogs catch ick? or the parasite that causes? I had to put my hand in the tank so i was wondering if i will get it? just in case my dog licks the water.. could they get it? How long will this ick parasite live in the tank?

  17. james Says:

    I am in the process of treating my tank and the white spots seem to have abated. I’m wondering what other precautions I should take with equipment that have not been immersed in the tank such as the carbon I took out of the power filter and the tubing for water changes, etc. I’m paranoid that they might have some residual ick on them even if they’re dry.

  18. genine Says:

    Hi I’v been given 4 large goldfish and I have found white spots on the head only thay came from a verry shallow pond also had two kois in the pond has anyone got some info please

  19. Rachel Says:

    We now have 4 goldfish in a 5 gallon tank (one died last week before the ick showed up on the smallest one). For two days, I’ve been leaving the light on in the tank to assure higher temp. for faster treatment of ick (first treatment was yesterday, so water must be 50% changed today). According to treatment instructions, I removed the carbon filter and kept the filter mechanism running. If the treatment is for at least 9 days, 3 treatments and 3 (50%) water changes, I also will need to treat the water for chlorine each time. How will the Malichite treatment interact with the chlorine removal treatment? I’m so very concerned because these goldfish are treasured dearly by my 4-year-old daughter and it will crush her if any more die.

  20. G@N$T@Y@LL Says:

    i have a questin about goldfish i have a oranda goldfishand i woke up on day and seen dhese little whit dots on its fore head wasnt a lot like 4 little dots and du u know how to determine the sex of goldfish cause i have been asking a lot of questions about that and the heatly diet i feed it is dried blood worms for a great treat or sometime goldfish flakes can u please reply to thiz ick fourm thnz peace out

  21. Brandi Says:

    Hi, I have treated my sons goldfish for ick and now where the ick was it is black is this normal or is this something else entirely? Thanks

  22. Chelsea Says:

    Hi, i have a question about the salt treatment. can i use the treatment in a tank that also includes healthy fish. I dont want to cause harm to my healthy fish. Or should i just quarantine my sick fish.

  23. rana Says:

    hi admin
    i have a black moor and a fantail in a 10 gallon tank. all water is good. brought home black moor from petsmart and it got ich on the 3rd day!
    so was treating it was tetra gold medica for 15 days. nothing worked. it went away on the 4th day and was back on the 5th day! heat is up. now maidenhead aquatics have said to use waterlife protozin. is this ok? they use that on their fish and they swear by it. so i have to treat like this: 1st,2nd,3rd and then 6th day
    why is this ich not budging? i have added salt. and heat is up to 80. what else can i do?!

  24. jellybelly Says:

    Hello Admin,

    About 5 days ago I noticed that one of my goldfish had ich. So I began treating the tank with ich medication and doing daily 25% water changes; however day before yesterday evening one of the goldfish was upside down on the bottom of the tank and this morning I found that same fish dead even though all signs of the ich parasite were gone. Also, over the last few days a different one of the goldfish in the same tank has not eaten anything. I can’t figure out what is wrong. All of the goldfish seem to have no white spots left however the one will not eat. Please help.

  25. Divya Says:

    Hi Admin,

    I noticed today that my goldfish have white particles lining their tails fins and eyes. The white particles appear more like cotton hanging off. Their behaviour seems very lethargic, and they used to be lively but they can barely swim up now. They dont even eat anymore. Is this ich and how should i treat their condition?

  26. matt Says:


    One of my 5 fish died today from ich.
    I am scared that another has it because it has the right symptoms. He is very old and I don’t want the salt or malachite green to effect the other fish in a bad way!

    What should i do?

  27. Jazzy Brown Says:

    2 of my Goldfish have gotten black spots on the gills towards the back & upper sides. This happened yesteday. Is this a form of ich? Will a salt water treatment help? If so how much per 10 gal. will I need? Does API Liquid Super Ick Cure really cause cancer? Please answer A.S.A.P before they all become infected. Thank you!!!

  28. Katelyn Says:

    Hi I just bought 2 young oranda goldfish and 1 young fantail goldfish. And have introduced them all to their tank but later in the day I noticed that the redcap oranda has white spots like salt all over its tail and a bit on its body. The fish that used to be in that tank all died of ich and fungal infections and when I finally got some treatment it was too late. I still have the medication and I was wondering whether to use it or not. I do not want to wait until it is too late like last time but I also don’t want to affect the other fish because they don’t seem to have it yet. I also do not have a quarantine tank so that is out of the question. Please answer soon I only just got these guys and I do not think I can handle another batch dying so soon.

  29. craig Says:

    hi i have two of my gold fish in a treatment tank and im using methylene blue for ick could u tell me how long the treatment takes and how often does the water need changing please ..cheers

  30. sanket Says:

    i had 9 goldfish of diffrent types i have aquarium within 2 years but this happened 1 st time that suddenly i had seen white spot on every goldfish of my aquarium and so i had given it regular treatment of drug purchased from aquraium but after 2 days wen i woke up at morning i have seen 5 of them were died…………………….
    remaing 4 are in fatal condition ……………………..so everybody pls help me to save my remaing fish i have also snails in my aquarium they are in my aquarium before 3 months ago are they reason of ick? or i have buyed new fish 7 days ago but it was healthy it ius a,live now but reaming fishes are dyinbg so is it a reason of ick? pls help mee………..

  31. Alisha Says:

    I have a 1 gallon fish tank with 3 gold fish in it they have ick I think what’s the best way to treat them

  32. Alisha Says:

    and the first 1 that was infected was completely orange and is now mostly black I’ve been using start right that says it says it treats ick been using it for about 3 weeks now and I have changing the water 100 percent twice in those 3 weeks

  33. Sande Says:

    Please give me assistance! We have had our tank of 5 goldfish for 9 months now. We had a difficult time getting our amonia under control but everything else in the tank is PERFECT! We do water changes every week (25 – 25%). We lost two fish this week and now appear to have ICK in the tank. All three fish are eating but are not as active as usual. Moby seems to be the worst. The tank is 46 gallons and has filtration adequate for ut to 75 gallons. I started using Malachite Green today. My question is that, if the fish are already compromised, do I start raising the temperature or just treat for 6 weeks? If so, what is the recommended protocol to ensure optimal treatment? The recommendation on the packaging is that we treat today, wait 48 hours, treat again, wait 48 hours and then do a 25% water change.

    I REALLY need advice!

  34. Suzy Says:

    I have 6 telescope fish in a 40 gallon 5 foot long x 13.5″ high tank. My biggest fish has one white spot about the size of the star above the eight on your key board. That eye is bigger than the other eye. Should I be concerned? I keep a very clean tank from ammonia, nitrites etc. Water changes twice a week. API liquid testing. Advice please

  35. Alicia Says:

    hello. I have a had my goldfish for 2 years and i recently got an algae eater and ever since my goldfish has not been looking good. She now has white stuff on her fins and i have been treating her with the “Ick” treatment. Is she going to die or what is going to happen to her?

  36. Cindy Says:

    My goldfish was bitten really bad by a taytar i had in the tank,so i moved it and i bought a tablet called TETRA Parasite Guard to put in the water.I am also using methylene,hoping it would help.That was a week ago this happened and now the fish is moving lively but on the places the other fish were biting is covered with a white fluffy stuff.Is that happening because the fish is curing and the scales are growing back or is that some kind of disease?

  37. Gwen Says:

    I added two new fancy goldfish to by 50 gallon tank. Two days later looked to have Ick. Treated with the treatment that comes from petsmart but I have had it a while. All the fish have died within the last 5 days. They looked terrible. I did several water changes to try and save them but nothing helped. Eyes turned red and their outer flesh even started to peel away. I feel terrible for killing all the fish but I have no idea what I did. I had the other fish for years before adding the new two. Any ideas what it could have been?

  38. Eric Says:

    I realized my goldfish were acting funny and went to local pet store and they sent me home with Ich treatment. It was the green stuff. after the first treatment are biggest goldfish died. I got home from work that day and constantly watched are other one and are new plecco and then this morning both of them are dead. I just purchased the plecco and 2 apple snails from Petsmart 10 days ago and now all my fish are dead and the snails are fine. What course of action should I take now with replacing the fish? Could the disease have come from the snails. The fish had white spots, flaky skin and cloudy eyes. what stinks is both are goldfish were carnival fish that my boys won and they had grown to be beautiful. The oldest was 5 years old. Thank you for any help that you are.

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