I have a planted community tank where everything, but my Corydoras are thriving. My Corys have greatly lost their color and have a white hue. It looks like layers of their skin is flaking off. Whatever this is seems to be slowly progressing from Cory to Cory and each Cory worsens daily.
I treated my tank for Ich about a month and a half ago. I had to dose for close to a month and did multiple water changes. It was towards the end of the treatment that I began noticing the discoloration and for the past couple of weeks it has been worsening.
I've been treating with API Melafix for almost a week now with no signs of improvement.
This Cory in the next picture has (what I assume is the same thing) by far worst and unique from what I've seen on any of my other Corys.
pH 6.8
Nitrates 20
Hardness 150
Nitrites 0
KH/Buffer 40
Temperature 78
My Tetra test strips don't show for Amonia.