Corydora Fin White Fuzz

Discussion in 'Freshwater Beginners' started by Ebelle, Jun 18, 2019.

  1. EbelleNew MemberMember

    Need help with this white fin fuzz on my false Julii Cory. I just noticed it today and have him in a breeder box. Will set up quarantine tank tomorrow but need to figure out what meds to get when I go to the store tomorrow.


    What is the water volume of the tank? 37 gallon
    How long has the tank been running? Tank has been running for 3 weeks, it was an upgrade from a 10 gallon that was transferred when I moved in end May.
    Does it have a filter? Aq 50 and Aq 30
    Does it have a heater? 2 x 100 watt
    What is the water temperature? Normally runs at 76 but I pushed it up to 80 after losing a Cory last week. Also the heat has made it go up to 84 some days.
    What is the entire stocking of this tank? (Please list all fish and inverts.) 18 neons, 4 panda corys, 8 false Julii, 10 pygmy corys, 6 nerites (2 small, 2 med, 2 large) and 12 red cherry shrimp

    How often do you change the water? 30% every week to 10 days
    How much of the water do you change? 30%
    What do you use to treat your water? Top fin water conditioner
    Do you vacuum the substrate or just the water?
    A bit of the substrate, but tough cos of the planted tank substrate. Using fluval plant and shrimp stratum.

    *Parameters - Very Important
    Did you cycle your tank before adding fish? I basically moved my AQ 30 that was on my 10 gallon over and added a AQ 50. So only mini cycle. Parameters are below.
    What do you use to test the water? API freshwater test kit
    What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

    Ammonia: 0
    Nitrite: 0
    Nitrate: about 30 (color is between 20 and 40)
    pH: 7.0

    How often do you feed your fish? Once a day
    How much do you feed your fish? Enough for tetras to finish in a couple of minutes and sinking wafers for the Cory's/inverts
    What brand of food do you feed your fish? Hikari
    Do you feed frozen or freeze-dried foods? No

    Illness & Symptoms
    How long have you had this fish? New fish, about 10 days in tank
    How long ago did you first notice these symptoms? Started seeing he was listless about 3 days ago
    In a few words, can you explain the symptoms? I noticed he wasn't coming to eat during mealtimes for the past 3 days and saw the white fuzz startin yesterday
    Have you started any treatment for the illness? No, need advice
    Was your fish physically ill or injured upon purchase? Did not seem to be
    How has its behavior and appearance changed, if at all? Left fin is entirely fuzzy white now.

    Explain your emergency situation in detail. (Please give a clear explanation of what is going on, include details from the beginning of the illness leading up to now)

    Need help to figure out what this Cory has. Just lost a panda Cory (whose tail rotted away and was inactive for about a week) and I hope not to lose more fish. All other fish in tank look good and happy.

    Attached Files:

  2. OceanviperNew MemberMember

    Maybe a type of fungus, I’m not the best when it comes to diseases. If I’m not mistaken there is another place on the forum for freshwater diseases and quarantine. Maybe post his there. Best of luck! Hope your Cory gets better!
  3. richie.pWell Known MemberMember

    Please enter @DoubleDutch I have a lot of confidence in this guy regarding cories
  4. MolassesNew MemberMember

    Looks to me like some sort of fungus infection. Not an expert, but anything fuzzy is usually something fungus related. If that's the case, I would get some fungus treatment. I know API makes some and you could probably find it at PetSmart. Never experienced this personally before though.
  5. WindChillNew MemberMember


    I've had a similar issue with my mollies and other livebearers. Since corys are small scale catfish it's important that you DONT OVERTREAT them with medication or salt. I work in fish health at a state fish hatchery and Columnaris or Saprolegnia look like your issue. When treating these I like to first add salt (use half a recommended dose or less for any catfish or inverts) and if that doesn't clear up the issue I like to use a copper sulfate based medicine (again, half the recommended FRESHWATER dose. This is very important to read the instructions.)

    In terms of your whole tank, the temperature is too high for any of the fish, I would recommend 72-76F and you will see improvement in fungal growths. Also, be sure to add a small amount of aquarium salt to your main tank if you notice any other fish with symptoms as this can be contagious.

    Best of luck!
  6. EbelleNew MemberMember

    I forgot that I already added salt when I first noticed a panda cory (that eventually died) having some white fuzz. I will lower the temp as much as I can and see if that helps. I will also add some salt when I do water change tomorrow.

    Thanks for the suggestions!
  7. DoubleDutchFishlore LegendMember

    What kind of Hikari food are you exactly feeding? The shape of the fish worries me a bit but that might be the pic.

    Looks like a wound that started fungussing.On the other hand there are several bacterial infections that look like fungus or have a secundairy fungal infection. They damage the skin so fungus can take its chance afterwards.