I have a platy that I've had for about 3.5 weeks. I quarantined her for 2.5 weeks before putting her into my 55 gallon tank. I've had columnaris deaths in the recent past, and most of the fish I have now are the survivors of it. This platy looked good when I bought her, but when I brought her home she seemed to have a bit of a film over one side of her body. I could only see it in certain lights. One of her eyes sometimes looks cloudy too, but again, only in certain lights. Very hard to see to the casual observer.
She's not doing well now, and I'm sure she was becoming ill when I brought her home, but of course its too late to take her back to the store now. I took her out of my big tank, as the last thing I need is the other fish catching whatever she has. She's still eating fairly well, but does isolate herself from the others and spends too much time at the top and near the filter. (From my columnaris deaths, I know this is not a good sign).
I have male guppies currently in my 10 gallon quarantine tank, so I have nowhere to put her! I finally decided to put her in a one gallon cube that I have and used the tank water, and added the appropriate amount of Seachem Kanaplex (Kanmycin) to her water. Problem is, I don't have a filter in there, and no heater. I know platies are more tolerant of cold water than a lot of other fish, but I'm worried about no filter and aeration. Can she stay in there long enough to get over her illness with no filter? And if so, how often should the water be changed, and what percentage? The temperature of the water wouldn't get below about 72 in the bathroom where I have her.