White spot on cory fin

[danielgraves]

So one of my bronze corydoras Has a white spot on it’s fin. Tank is a 20 gal, 0,0,<20 params. Tank’s been stable for a year now. This cory I got a few months ago. I do 50% wc weekly. Anyone have any ideas what the issue could be? Can’t use my go-to salt treatment since it’s a cory.

[sdlTBfanUK]

From the little detail supplied it sounds like Ich/whitespot? This is usually down to bad water! I see you do a large water change weekly so it probably isn't water cleanliness, so it may simply be that your water parameters aren't suited to the fishes requirement based on the parameters it lived in before?

What else lives in the tank? I assume there are a lot if you need to do 50% water change per week, I only do 15-20% per week with fish, too much may stress the fish/other occupants and probably unneccesary, especially if you don't add the new water slowly (I use a dripper)!

Do you know your full set of water parameters?

The little I have read involves the ich reproducing in the substrate so I guess that maked bottom dwellers more at risk. It is quite a common disease and there are various medications, dependant on what is available in your country? My fish have necer had it so I can't comment on which may be best.

I hope someone who has this type of fish (I never have) may have more insight and useful advice!

Simon

[jayc]

What are your other parameters?

A healthy environment for a particular species of fish isn't down to just having no ammonia, nitrite, and low nitrates.

You have to get temps, pH, GH and to a lesser extent KH at a suitable range as well.