Misery Loves Company

I use the word "casualty", because there are no deaths yet, but some of the cories aren't looking too good. While I was making my nightly observations, I saw a couple cories were breathing quite heavily. They also had frayed fins. I found myself asking, what came first, the fin injuries or the breathing? Also, I thought perhaps, that O2 levels were low, as I think warmer water cannot hold as much oxygen. However, only the cories with frayed fins were breathing heavily, and a quick online search revealed that rapid breathing is usually associated with some disease or other.

Knowing that the two cories were probably sick with something, and not wanting to medicate the entire 30-gallon tank, I removed the two of them, and I placed them in the converted 5-gallon hospital tank with the other cory. I'm hoping the medication is still sufficiently strong to help, and I imagine they're all in for a second dose before I drop them back in the 30-gallon.

Just in case, I went ahead and added some aeration to the HOB filter. My thought is that the surface area of the filter is small, so I'm hoping not to displace too much CO2. It's likely unnecessary, though, as no other cories, much less other species, are showing any signs of undue stress or disease. In the back of my mind, though, I still worry about the water temperature being high, and causing collateral problems.