I picked up 6 sterbei cories last Saturday, and they're now in my 120L (they're on their own, so are being quarantined). I will be testing the water when I get home from work, and will post it then.

I noticed last night that one of the smaller ones has a light patch just to his left of his dorsal fin. There is nothing to indicate to me that there is any kind of fungal infection or ich. The fish is very active; eating and swimming happily, and I haven't seen him scratching against anything. They're being fed shrimp pellets, and there are definitely small inverts like midge larvae in the water too. None of the other cories have a similar patch.

I know that it's practically impossible to know what could be wrong just from a description, I guess I'm just wondering if it's something I should worry about or not. My gut says that it's probably just an abrasion, but it's so frustrating that you can't get them to hold still so you can get a good look.