It looks like a white zit that is slowly getting a little bigger - no redness, but not cauliflower look either.

We are in the process of trying to sell our house right now with people in and out and open house. If there's any way around, I'd like to not set up a hospital tank. since, whatever it is, everyone's probably been exposed to, can I treat the entire tank (keep in mind an otto and 2 cory cats)?

If so, what antibiotic or other med would you suggest. Would Kana be o.k.?