So long as you are finding stuff in the bucket and it is an out bucket, nothing is worse. I imagine you do this Peter, but for the casual reading it may seem like an unreasonable expense. At certain times you don't want to use an "in bucket" as an outbucket Compare a couple of dollar bucket with losses from any of a number of common diseases.

That out bucket can also be the one used for cleaning paint brushes, using a soap or ammonia solution on the floor. You are still just buying one bucket for the fish in most cases.

In time one may buy a couple of buckets. Dark black buckets are my out buckets for anything suspect. (I got a price I couldn't pass up, on a couple of industrial grade ones.) The inexpensive light colored or white ones from bakeries or the hardware store sales insure that, however peroccupied one is, clean new water isn't administered in a suspect bucket.

Even with the "nasty" bucket, there is always a freezing night like this evening. And in the summer, they may get the bleach solution from a cleaned out tank, before it is dumped down a toilet or laundry room sink.

Getting back to your observation about healthy looking vs unhealthy looking fishes,I think you are on to something. You've read Houde's book since I have. Is that where it suggested that female guppies will refuse diseased males? They seem to be able to tell.

That might be a que to deworm a tank.