ooooo that is one long and tragic story.
they were doing great, but one very cold spring day someone in the house decided to put the bowl outside for the whole day and night and they basically died overnight because of very cold temps. I brought in the bowl then next day and none were alive. This happened last spring. I've had yellows in here ever since.
Lame since around the same time i had PFRs outside in a huge 40gallon tub in the same cold (though their tub had a heater) and they did fine over the course of weeks at low 40Fs, maybe less.