Corydora Infection Every Few Months!?

[Colu]

Good to hear your Cory have recovered 

[Mitch_ScruffyCityAquatics]

It has been several months without any more issues with the cories. I periodically run the UV sterilizer, I regularly feed with Vitachem infused foods, and I’ve been doing regular weekly water changes even though my parameters remain the same with every test. 
 

The little Molly that was staying on the bottom has continued to do so. She does swim up to eat, but If aim looking at the tank from a distance she is resting in the sand, and now there are four more doing it. 
 

It’s possible I’ve overfed trying to feed the cories. The Mollies won’t stop eating as long as there is food in the tank. I have removed the inflicted mollies and placed them in QT. I’ve fasted them and fed them a pea. Today will be a day without food again, and I plan on feeding them peas again tomorrow. 
 

How long would you wait before you treated them with Maracyn? Keep in mind they were all treated with Maracyn back in December in my big tank. 
 

Thank you all for all of your help. 

Edited March 17, 2021 by Mitch Norton

[Colu]

You can treat now or could wait and see if fasting  peas works 

[Mitch_ScruffyCityAquatics]

I started treatment. Yesterday was day 5. I have had another fish in the main tank begin resting in the bottom. I ordered two large boxes of Maracyn from Aquarium Co-Op this weekend and it should arrive today. I guess I am treating the main tank. 

[spookshow69]

I know this is an old comment thread. Corydoras are extremely sensitive to salt. Do not use salt on Corydoras. This could be Collumaris too. I’ve been through this. I treated them with everything I could think of. Then I finally got some Fritz, and the fish finally healed. She’s gone now. I had her for years. Then I had an automatic feeder that didn’t work while I was gone, and lost her. I believe it was Collumaris. It’s very difficult to treat, and it looks different sometimes. You will get the wooly growths with it. I actually may be fighting it again with another Cory. I started Fritz immediately this time. I’m not sure that’s what’s wrong, but I’ll try it first. My other fish did not get these growths, but she lost her whiskers, and started getting mouth rot. If you see their whiskers gone it is not from your gravel. It’s a bacterial, or fungal. Most likely Collumaris. I’m putting this on here so people see it. They are also very sensitive to Melafix. 

[Mitch_ScruffyCityAquatics]

thanks @spookshow69 This did eventually go away. I have several happy Corydora in the tank now with no issues since the last loss in this thread. I’m not sure what it was, but it always looked bacterial and never had fluffy or raised areas. 
 

On salt, I’ve spent a lot of time researching this. It is true that cories are more sensitive to salt than say livebearers, but salt appear to be a good treatment for many problems. It appears the trick is small dosage and short treatment. Check out Bob Steenfott’s video on it.