How long is ich cycle?

Black Clover · Dec 1, 2023

Hi all.
I had a problem with salt water ich.
How long do you guys recommend the DT stay empty to essentially starve the ich. (there are only inverts in there right now).
I was not able to treat DT so this was my only solution.
I'm reading that to kill ich, remove hosts, which I did. Then wait for ich cycle to die.
So here is where there are lots of different answers....
Is it 4 weeks, 6 weeks, 76 days, other???
Thanks!

Timfish · Dec 1, 2023

Here's a paper by University of Florida. https://edis.ifas.ufl.edu/publication/fa164

Part of the reason there are different answers is temperature is a big factor. There's also different degrees of resistance between fish species and individual fish may develop resistance. I suspect, based on my experiences over the last 4 decades there may be strains with different degrees of virulence, but I want to emphasize I have not found any research that would support that suspicion.

nereefpat · Dec 1, 2023

The current recommendation here is 45 days at 82 degrees. 72 days was in a sterile lab at really low temperatures. It was a little silly that caught on in the hobby.

It's a bell curve type thing. The longer you wait, and the higher the temperature, the closer to 100% sure you can be.

Black Clover · Dec 1, 2023

Thanks!
My water is usually at about 78 degrees. I'm thinking that 6 weeks should do the trick.

And after reading that great article sent by Timfish, it sound like my clown fish will have built an immunity to it.

Black Clover · Dec 1, 2023

Timfish said:
Here's a paper by University of Florida. https://edis.ifas.ufl.edu/publication/fa164

Part of the reason there are different answers is temperature is a big factor. There's also different degrees of resistance between fish species and individual fish may develop resistance. I suspect, based on my experiences over the last 4 decades there may be strains with different degrees of virulence, but I want to emphasize I have not found any research that would support that suspicion.

Wow! Great article. Thanks!!

Quoted from https://edis.ifas.ufl.edu/publication/fa164:

"As is seen with other diseases, general fish health and environmental factors including water quality will affect the status of the fish's immune system and may worsen the effects of an infection. If the immune status of the fish is compromised or if environmental factors are less than optimal, Cryptocaryon infection will be even more explosive and harmful.

Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997)....

...A number of factors determine how severe the disease and mortalities will be and the length of the parasite life cycle. These factors include the strain of Cryptocaryon, the temperature and salinity of the water, the species and age of the fish and their general immune status, previous exposure to the parasite, the number of infective parasites present, and the dissolved oxygen concentration of the water. The life cycle can last from 6–11 weeks, but an average parasite life cycle appears to be 1–2 weeks. However, because the time required until release of infective theronts after tomont formation varies so widely, prolonged treatment periods (3–6 weeks) are recommended. Longer treatment time may be necessary.

Treatments recommended in this publication for any given outbreak should provide significant mitigation of disease. Copper sulfate pentahydrate appears to be the most effective treatment to date. Chloroquine and salinity, as well as formalin, have also proven to have some effectiveness. If the Cryptocaryon strain affecting your fish is tolerant of low salinity, however, hyposalinity will not be an effective control.

Quarantine of any new fish for 30–90 days before introducing them into an established population will provide time for observation, treatment, and reduction of spread."