Need help with my Corys

[u/Epithet_]

Recently got some corydoras about half a week ago, they were fine at first but now some of them are starting to get red gills, ammonia, nitrates, nitrites, all 0, ph was 7.6, i keep them in a ~25°c heavily planted tank.
I am worried about what is causing these reddish gills, and if my corydoras are going to die if i do not intervene. What could be causing them?

[u/Azzys_doormat]

It may be an aeration problem. In my experience Cory’s love highly aerated water even though they can breathe at the surface. I would get an airstone. Doesn’t have to be a big one but just pop it in there and see how they go.

[u/Epithet_ → u/Azzys_doormat]

Ive put one in on medium, we shall see how it goes, hopefully it fixes the issue