experiment with six tiny fish.
I was warned that the "feeder fish" that I was using for my experiment were not guaranteed to be healthy, and that's why they were "feeder fish": they were going to die soon anyway. Might as well feed somebody's bigger fish.
So half of them have died, and the other half are apparently thriving. They've been playing around the surface of the water. I use a lot of their water, probably replacing half of their water daily.
The plants are happy. The fish are happy.
Maybe this will be a good thing?